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92 results on '"Dagorn L"'

1. The heterogeneous spatial and temporal patterns of behavior of small pelagic fish in an array of Fish Aggregating Devices (FADs)

Author

Capello, M., Soria, M., Cotel, P., Potin, G., Dagorn, L., and Fréon, P.

Subjects
Quantitative Biology - Populations and Evolution
Abstract

Identifying spatial and temporal patterns can reveal the driving factors that govern the behavior of fish in their environment. In this study, we characterized the spatial and temporal occupation of 37 acoustically tagged bigeye scads (Selar Crumenophthalmus) in an array of shallow Fish Aggregating Devices (FADs) to clarify the mechanism that leads fish to associate with FADs. A comparison of the number of visits and residence times exhibited by the fish at different FADs revealed a strong variability over the array of FADS, with the emergence of a leading FAD, which recorded the majority of visits and retained the fish for a longer period of time. We found diel variability in the residence times, with fish associated at daytime and exploring the array of FADs at nighttime. We demonstrated that this diel temporal pattern was amplified in the leading FAD. We identified a 24-hour periodicity for a subset of individuals aggregated to the leading FAD, thus suggesting that those fish were able to find this FAD after night excursions. The modeling of fish movements based on a Monte Carlo sampling of inter-FAD transitions revealed that the observed spatial heterogeneity in the number of visits could not be explained through simple array-connectivity arguments. Similarly, we demonstrated that the high residence times recorded at the leading FAD were not due to the spatial arrangement of individual fish having different associative characters. We discussed the relationships between these patterns of association with the FADs, the exploration of the FAD array and the possible effects of social interactions and environmental factors., Comment: 21 pages, 9 figures + 2 supplementary figures

Published
2012

2. Role of current and daylight variations on small-pelagic fish aggregations around a coastal FAD from accurate acoustic tracking

Author

Capello, M., Soria, M., Potin, G., Cotel, P., and Dagorn, L.

Subjects
Quantitative Biology - Populations and Evolution
Abstract

We monitored twelve acoustically-tagged small pelagic fish (Selar crumenophthalmus) around a floating object in shallow water, playing the role of a coastal fish aggregating device (FAD). We characterized the response of the tagged-fish aggregation to varying current strengths and daylight. We found that the current induced a displacement of the aggregation upstream of the FAD, at distances that were increasing with the current strength. We gave evidence, of an expansion and a higher coordination in the aggregation at dusk, with increasing swimming speed, distances among congeners and alignment. We discussed possible scenarios where fish polarization increases at dusk and proposed complementary measurements in future experiments that could confirm our findings., Comment: 16 pages, 5 figures

Published
2012

4. Diving into the vertical dimension of elasmobranch movement ecology

Author

Andrzejaczek, S., Lucas, T.C.D., Goodman, M.C., Hussey, N.E., Armstrong, A.J., Carlisle, A., Coffey, D.M., Gleiss, A.C., Huveneers, C., Jacoby, D.M.P., Meekan, M.G., Mourier, J., Peel, L.R., Abrantes, K., Afonso, A.S., Ajemian, M.J., Anderson, B.N., Anderson, S.D., Araujo, G., Armstrong, A.O., Bach, P., Barnett, A., Bennett, M.B., Bezerra, N.A., Bonfil, R., Boustany, A.M., Bowlby, H.D., Branco, I., Braun, C.D., Brooks, E.J., Brown, J., Burke, P.J., Butcher, P., Castleton, M., Chapple, T.K., Chateau, O., Clarke, M., Coelho, R., Cortés, E., Couturier, L.I.E., Cowley, P.D., Croll, D.A., Cuevas, J.M., Curtis, T.H., Dagorn, L., Dale, J.J., Daly, R., Dewar, H., Doherty, P.D., Domingo, A., Dove, A.D.M., Drew, M., Dudgeon, C.L., Duffy, C.A.J., Elliott, R.G., Ellis, J.R., Erdmann, M.V., Farrugia, T.J., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Finucci, B., Fischer, C., Fitzpatrick, R., Forget, F., Forsberg, K., Francis, M.P., Franks, B.R., Gallagher, A.J., Galván-Magaña, F., García, M.L., Gaston, T.F., Gillanders, B.M., Gollock, M.J., Green, J.R., Green, S., Griffiths, C.A., Hammerschlag, N., Hasan, A., Hawkes, L.A., Hazin, F., Heard, M., Hearn, A., Hedges, K.J., Henderson, S.M., Holdsworth, J., Holland, K.N., Howey, L.A., Hueter, R.E., Humphries, N.E., Hutchinson, M., Jaine, F.R.A., Jorgensen, S.J., Kanive, P.E., Labaja, J., Lana, F.O., Lassauce, H., Lipscombe, R.S., Llewellyn, F., Macena, B.C.L., Mambrasar, R., McAllister, J.D., McCully Phillips, S.R., McGregor, F., McMillan, M.N., McNaughton, L.M., Mendonça, S.A., Meyer, C.G., Meyers, M., Mohan, J.A., Montgomery, J.C., Mucientes, G., Musyl, M.K., Nasby-Lucas, N., Natanson, L.J., O’Sullivan, J.B., Oliveira, P., Papastamtiou, Y.P., Patterson, T.A., Pierce, S.J., Queiroz, N., Radford, C.A., Richardson, A.J., Righton, D., Rohner, C.A., Royer, M.A., Saunders, R.A., Schaber, M., Schallert, R.J., Scholl, M.C., Seitz, A.C., Semmens, J.M., Setyawan, E., Shea, B.D., Shidqi, R.A., Shillinger, G.L., Shipley, O.N., Shivji, M.S., Sianipar, A.B., Silva, J.F., Sims, D.W., Skomal, G.B., Sousa, L.L., Southall, E.J., Spaet, J.L.Y., Stehfest, K.M., Stevens, G., Stewart, J.D., Sulikowski, J.A., Syakurachman, I., Thorrold, S.R., Thums, M., Tickler, D., Tolloti, M.T., Townsend, K.A., Travassos, P., Tyminski, J.P., Vaudo, J.J., Veras, D., Wantiez, L., Weber, S.B., Wells, R.J.D., Weng, K.C., Wetherbee, B.M., Williamson, J.E., Witt, M.J., Wright, S., Zilliacus, K., Block, B.A., Curnick, D.J., Andrzejaczek, S., Lucas, T.C.D., Goodman, M.C., Hussey, N.E., Armstrong, A.J., Carlisle, A., Coffey, D.M., Gleiss, A.C., Huveneers, C., Jacoby, D.M.P., Meekan, M.G., Mourier, J., Peel, L.R., Abrantes, K., Afonso, A.S., Ajemian, M.J., Anderson, B.N., Anderson, S.D., Araujo, G., Armstrong, A.O., Bach, P., Barnett, A., Bennett, M.B., Bezerra, N.A., Bonfil, R., Boustany, A.M., Bowlby, H.D., Branco, I., Braun, C.D., Brooks, E.J., Brown, J., Burke, P.J., Butcher, P., Castleton, M., Chapple, T.K., Chateau, O., Clarke, M., Coelho, R., Cortés, E., Couturier, L.I.E., Cowley, P.D., Croll, D.A., Cuevas, J.M., Curtis, T.H., Dagorn, L., Dale, J.J., Daly, R., Dewar, H., Doherty, P.D., Domingo, A., Dove, A.D.M., Drew, M., Dudgeon, C.L., Duffy, C.A.J., Elliott, R.G., Ellis, J.R., Erdmann, M.V., Farrugia, T.J., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Finucci, B., Fischer, C., Fitzpatrick, R., Forget, F., Forsberg, K., Francis, M.P., Franks, B.R., Gallagher, A.J., Galván-Magaña, F., García, M.L., Gaston, T.F., Gillanders, B.M., Gollock, M.J., Green, J.R., Green, S., Griffiths, C.A., Hammerschlag, N., Hasan, A., Hawkes, L.A., Hazin, F., Heard, M., Hearn, A., Hedges, K.J., Henderson, S.M., Holdsworth, J., Holland, K.N., Howey, L.A., Hueter, R.E., Humphries, N.E., Hutchinson, M., Jaine, F.R.A., Jorgensen, S.J., Kanive, P.E., Labaja, J., Lana, F.O., Lassauce, H., Lipscombe, R.S., Llewellyn, F., Macena, B.C.L., Mambrasar, R., McAllister, J.D., McCully Phillips, S.R., McGregor, F., McMillan, M.N., McNaughton, L.M., Mendonça, S.A., Meyer, C.G., Meyers, M., Mohan, J.A., Montgomery, J.C., Mucientes, G., Musyl, M.K., Nasby-Lucas, N., Natanson, L.J., O’Sullivan, J.B., Oliveira, P., Papastamtiou, Y.P., Patterson, T.A., Pierce, S.J., Queiroz, N., Radford, C.A., Richardson, A.J., Righton, D., Rohner, C.A., Royer, M.A., Saunders, R.A., Schaber, M., Schallert, R.J., Scholl, M.C., Seitz, A.C., Semmens, J.M., Setyawan, E., Shea, B.D., Shidqi, R.A., Shillinger, G.L., Shipley, O.N., Shivji, M.S., Sianipar, A.B., Silva, J.F., Sims, D.W., Skomal, G.B., Sousa, L.L., Southall, E.J., Spaet, J.L.Y., Stehfest, K.M., Stevens, G., Stewart, J.D., Sulikowski, J.A., Syakurachman, I., Thorrold, S.R., Thums, M., Tickler, D., Tolloti, M.T., Townsend, K.A., Travassos, P., Tyminski, J.P., Vaudo, J.J., Veras, D., Wantiez, L., Weber, S.B., Wells, R.J.D., Weng, K.C., Wetherbee, B.M., Williamson, J.E., Witt, M.J., Wright, S., Zilliacus, K., Block, B.A., and Curnick, D.J.

Abstract

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.

Published
2022

5. Biodegradable DFADs: Current status and prospects

Author

Zudaire, I., Moreno, G., Murua, H., Murua, J., Tolotti, M.T., Roman, M., Hall, M., López, J., Grande, M., Merino, G., Escalle, L., Hamer, P., Basurko, O.C., Capello, M., Dagorn, L., Ramos, María Lourdes, Abascal, Francisco Javier, Báez, José Carlos, Pascual-Alayón, Pedro José, Deniz, Santiago, Santiago, J., Zudaire, I., Moreno, G., Murua, H., Murua, J., Tolotti, M.T., Roman, M., Hall, M., López, J., Grande, M., Merino, G., Escalle, L., Hamer, P., Basurko, O.C., Capello, M., Dagorn, L., Ramos, María Lourdes, Abascal, Francisco Javier, Báez, José Carlos, Pascual-Alayón, Pedro José, Deniz, Santiago, and Santiago, J.

Abstract

Until recently, dFAD structure, materials and designs have remained quite rudimentary and virtually the same since their discovery, characterized by the increase of the dimensions and prevailing heavy use of plastic components. Biodegradable materials are called to be an important part of the solution, as they can faster degrade in the environment, free of toxins and heavy metals, reducing their lifespan, and preventing them from accumulating in sensitive areas once they are abandoned, lost or discarded. During last decades, regulatory measures at tRFMOs have advanced in the gradual implementation of biodegradable materials in dFAD constructions together with other measures limiting the number of active dFADs and the use of netting materials. However, more clarity is needed starting with a standardised definition of biodegradable dFADs among tRFMOs, to provide operational guidance. Research with those natural and synthetic materials is required, along with updated data collection for monitoring standards, as well as alternative and complementary actions need to be explored to contribute to minimising dFAD adverse effects on environment. Acknowledging the current difficulties for the implementation of fully biodegradable dFADs a stepwise process towards the implementation of fully biodegradable dFADs should be considered.

Published
2022

7. Reply to: Shark mortality cannot be assessed by fishery overlap alone

Author

Queiroz, N, Humphries, NE, Couto, A, Vedor, M, da Costa, I, Sequeira, AMM, Mucientes, G, Santos, AM, Abascal, FJ, Abercrombie, DL, Abrantes, K, Acuña-Marrero, D, Afonso, AS, Afonso, P, Anders, D, Araujo, G, Arauz, R, Bach, P, Barnett, A, Bernal, D, Berumen, ML, Lion, SB, Bezerra, NPA, Blaison, AV, Block, BA, Bond, ME, Bonfil, R, Bradford, RW, Braun, CD, Brooks, EJ, Brooks, A, Brown, J, Bruce, BD, Byrne, ME, Campana, SE, Carlisle, AB, Chapman, DD, Chapple, TK, Chisholm, J, Clarke, CR, Clua, EG, Cochran, JEM, Crochelet, EC, Dagorn, L, Daly, R, Cortés, DD, Doyle, TK, Drew, M, Duffy, CAJ, Erikson, T, Espinoza, E, Ferreira, LC, Ferretti, F, Filmalter, JD, Fischer, GC, Fitzpatrick, R, Fontes, J, Forget, F, Fowler, M, Francis, MP, Gallagher, AJ, Gennari, E, Goldsworthy, SD, Gollock, MJ, Green, JR, Gustafson, JA, Guttridge, TL, Guzman, HM, Hammerschlag, N, Harman, L, Hazin, FHV, Heard, M, Hearn, AR, Holdsworth, JC, Holmes, BJ, Howey, LA, Hoyos, M, Hueter, RE, Hussey, NE, Huveneers, C, Irion, DT, Jacoby, DMP, Jewell, OJD, Johnson, R, Jordan, LKB, Joyce, W, Keating Daly, CA, Ketchum, JT, Klimley, AP, Kock, AA, Koen, P, Ladino, F, Lana, FO, Lea, JSE, Llewellyn, F, Lyon, WS, MacDonnell, A, Macena, BCL, Marshall, H, McAllister, JD, Queiroz, N, Humphries, NE, Couto, A, Vedor, M, da Costa, I, Sequeira, AMM, Mucientes, G, Santos, AM, Abascal, FJ, Abercrombie, DL, Abrantes, K, Acuña-Marrero, D, Afonso, AS, Afonso, P, Anders, D, Araujo, G, Arauz, R, Bach, P, Barnett, A, Bernal, D, Berumen, ML, Lion, SB, Bezerra, NPA, Blaison, AV, Block, BA, Bond, ME, Bonfil, R, Bradford, RW, Braun, CD, Brooks, EJ, Brooks, A, Brown, J, Bruce, BD, Byrne, ME, Campana, SE, Carlisle, AB, Chapman, DD, Chapple, TK, Chisholm, J, Clarke, CR, Clua, EG, Cochran, JEM, Crochelet, EC, Dagorn, L, Daly, R, Cortés, DD, Doyle, TK, Drew, M, Duffy, CAJ, Erikson, T, Espinoza, E, Ferreira, LC, Ferretti, F, Filmalter, JD, Fischer, GC, Fitzpatrick, R, Fontes, J, Forget, F, Fowler, M, Francis, MP, Gallagher, AJ, Gennari, E, Goldsworthy, SD, Gollock, MJ, Green, JR, Gustafson, JA, Guttridge, TL, Guzman, HM, Hammerschlag, N, Harman, L, Hazin, FHV, Heard, M, Hearn, AR, Holdsworth, JC, Holmes, BJ, Howey, LA, Hoyos, M, Hueter, RE, Hussey, NE, Huveneers, C, Irion, DT, Jacoby, DMP, Jewell, OJD, Johnson, R, Jordan, LKB, Joyce, W, Keating Daly, CA, Ketchum, JT, Klimley, AP, Kock, AA, Koen, P, Ladino, F, Lana, FO, Lea, JSE, Llewellyn, F, Lyon, WS, MacDonnell, A, Macena, BCL, Marshall, H, and McAllister, JD

Published
2021

8. Reply to: Shark mortality cannot be assessed by fishery overlap alone

Author

Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., da Costa, I., Sequeira, A.M.M., Mucientes, G., Santos, A.M., Abascal, F.J., Abercrombie, D.L., Abrantes, K., Acuña-Marrero, D., Afonso, A.S., Afonso, P., Anders, D., Araujo, G., Arauz, R., Bach, P., Barnett, A., Bernal, D., Berumen, M.L., Lion, S.B., Bezerra, N.P.A., Blaison, A.V., Block, B.A., Bond, M.E., Bonfil, R., Bradford, R.W., Braun, C.D., Brooks, E.J., Brooks, A., Brown, J., Bruce, B.D., Byrne, M.E., Campana, S.E., Carlisle, A.B., Chapman, D.D., Chapple, T.K., Chisholm, J., Clarke, C.R., Clua, E.G., Cochran, J.E.M., Crochelet, E.C., Dagorn, L., Daly, R., Cortés, D.D., Doyle, T.K., Drew, M., Duffy, C.A.J., Erikson, T., Espinoza, E., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Fischer, G.C., Fitzpatrick, R., Fontes, J., Forget, F., Fowler, M., Francis, M.P., Gallagher, A.J., Gennari, E., Goldsworthy, S.D., Gollock, M.J., Green, J.R., Gustafson, J.A., Guttridge, T.L., Guzman, H.M., Hammerschlag, N., Harman, L., Hazin, F.H.V., Heard, M., Hearn, A.R., Holdsworth, J.C., Holmes, B.J., Howey, L.A., Hoyos, M., Hueter, R.E., Hussey, N.E., Huveneers, C., Irion, D.T., Jacoby, D.M.P., Jewell, O.J.D., Johnson, R., Jordan, L.K.B., Joyce, W., Keating Daly, C.A., Ketchum, J.T., Klimley, A.P., Kock, A.A., Koen, P., Ladino, F., Lana, F.O., Lea, J.S.E., Llewellyn, F., Lyon, W.S., MacDonnell, A., Macena, B.C.L., Marshall, H., McAllister, J.D., Meÿer, M.A., Morris, J.J., Nelson, E.R., Papastamatiou, Y.P., Peñaherrera-Palma, C., Pierce, S.J., Poisson, F., Quintero, L.M., Richardson, A.J., Rogers, P.J., Rohner, C.A., Rowat, D.R.L., Samoilys, M., Semmens, J.M., Sheaves, M., Shillinger, G., Shivji, M., Singh, S., Skomal, G.B., Smale, M.J., Snyders, L.B., Soler, G., Soria, M., Stehfest, K.M., Thorrold, S.R., Tolotti, M.T., Towner, A., Travassos, P., Tyminski, J.P., Vandeperre, F., Vaudo, J.J., Watanabe, Y.Y., Weber, S.B., Wetherbee, B.M., White, T.D., Williams, S., Zárate, P.M., Harcourt, R., Hays, G.C., Meekan, M.G., Thums, M., Irigoien, X., Eguíluz, V.M., Duarte, C.M., Sousa, L.L., Simpson, S.J., Southall, E.J., Sims, D.W., Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., da Costa, I., Sequeira, A.M.M., Mucientes, G., Santos, A.M., Abascal, F.J., Abercrombie, D.L., Abrantes, K., Acuña-Marrero, D., Afonso, A.S., Afonso, P., Anders, D., Araujo, G., Arauz, R., Bach, P., Barnett, A., Bernal, D., Berumen, M.L., Lion, S.B., Bezerra, N.P.A., Blaison, A.V., Block, B.A., Bond, M.E., Bonfil, R., Bradford, R.W., Braun, C.D., Brooks, E.J., Brooks, A., Brown, J., Bruce, B.D., Byrne, M.E., Campana, S.E., Carlisle, A.B., Chapman, D.D., Chapple, T.K., Chisholm, J., Clarke, C.R., Clua, E.G., Cochran, J.E.M., Crochelet, E.C., Dagorn, L., Daly, R., Cortés, D.D., Doyle, T.K., Drew, M., Duffy, C.A.J., Erikson, T., Espinoza, E., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Fischer, G.C., Fitzpatrick, R., Fontes, J., Forget, F., Fowler, M., Francis, M.P., Gallagher, A.J., Gennari, E., Goldsworthy, S.D., Gollock, M.J., Green, J.R., Gustafson, J.A., Guttridge, T.L., Guzman, H.M., Hammerschlag, N., Harman, L., Hazin, F.H.V., Heard, M., Hearn, A.R., Holdsworth, J.C., Holmes, B.J., Howey, L.A., Hoyos, M., Hueter, R.E., Hussey, N.E., Huveneers, C., Irion, D.T., Jacoby, D.M.P., Jewell, O.J.D., Johnson, R., Jordan, L.K.B., Joyce, W., Keating Daly, C.A., Ketchum, J.T., Klimley, A.P., Kock, A.A., Koen, P., Ladino, F., Lana, F.O., Lea, J.S.E., Llewellyn, F., Lyon, W.S., MacDonnell, A., Macena, B.C.L., Marshall, H., McAllister, J.D., Meÿer, M.A., Morris, J.J., Nelson, E.R., Papastamatiou, Y.P., Peñaherrera-Palma, C., Pierce, S.J., Poisson, F., Quintero, L.M., Richardson, A.J., Rogers, P.J., Rohner, C.A., Rowat, D.R.L., Samoilys, M., Semmens, J.M., Sheaves, M., Shillinger, G., Shivji, M., Singh, S., Skomal, G.B., Smale, M.J., Snyders, L.B., Soler, G., Soria, M., Stehfest, K.M., Thorrold, S.R., Tolotti, M.T., Towner, A., Travassos, P., Tyminski, J.P., Vandeperre, F., Vaudo, J.J., Watanabe, Y.Y., Weber, S.B., Wetherbee, B.M., White, T.D., Williams, S., Zárate, P.M., Harcourt, R., Hays, G.C., Meekan, M.G., Thums, M., Irigoien, X., Eguíluz, V.M., Duarte, C.M., Sousa, L.L., Simpson, S.J., Southall, E.J., and Sims, D.W.

Published
2021

9. Reply to: Caution over the use of ecological big data for conservation

Author

Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., da Costa, I., Sequeira, A.M.M., Mucientes, G., Santos, A.M., Abascal, F.J., Abercrombie, D.L., Abrantes, K., Acuña-Marrero, D., Afonso, A.S., Afonso, P., Anders, D., Araujo, G., Arauz, R., Bach, P., Barnett, A., Bernal, D., Berumen, M.L., Lion, S.B., Bezerra, N.P.A., Blaison, A.V., Block, B.A., Bond, M.E., Bonfil, R., Braun, C.D., Brooks, E.J., Brooks, A., Brown, J., Byrne, M.E., Campana, S.E., Carlisle, A.B., Chapman, D.D., Chapple, T.K., Chisholm, J., Clarke, C.R., Clua, E.G., Cochran, J.E.M., Crochelet, E.C., Dagorn, L., Daly, R., Cortés, D.D., Doyle, T.K., Drew, M., Duffy, C.A.J., Erikson, T., Espinoza, E., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Fischer, G.C., Fitzpatrick, R., Fontes, J., Forget, F., Fowler, M., Francis, M.P., Gallagher, A.J., Gennari, E., Goldsworthy, S.D., Gollock, M.J., Green, J.R., Gustafson, J.A., Guttridge, T.L., Guzman, H.M., Hammerschlag, N., Harman, L., Hazin, F. H.V., Heard, M., Hearn, A.R., Holdsworth, J.C., Holmes, B.J., Howey, L.A., Hoyos, M., Hueter, R.E., Hussey, N.E., Huveneers, C., Irion, D.T., Jacoby, D.M.P., Jewell, O.J.D., Johnson, R., Jordan, L.K.B., Joyce, W., Keating Daly, C.A., Ketchum, J.T., Klimley, A.P., Kock, A.A., Koen, P., Ladino, F., Lana, F.O., Lea, J.S.E., Llewellyn, F., Lyon, W.S., MacDonnell, A., Macena, B.C.L., Marshall, H., McAllister, J.D., Meÿer, M.A., Morris, J.J., Nelson, E.R., Papastamatiou, Y.P., Peñaherrera-Palma, C., Pierce, S.J., Poisson, F., Quintero, L.M., Richardson, A.J., Rogers, P.J., Rohner, C.A., Rowat, D.R.L., Samoilys, M., Semmens, J.M., Sheaves, M., Shillinger, G., Shivji, M., Singh, S., Skomal, G.B., Smale, M.J., Snyders, L.B., Soler, G., Soria, M., Stehfest, K.M., Thorrold, S.R., Tolotti, M.T., Towner, A., Travassos, P., Tyminski, J.P., Vandeperre, F., Vaudo, J.J., Watanabe, Y.Y., Weber, S.B., Wetherbee, B.M., White, T.D., Williams, S., Zárate, P.M., Harcourt, R., Hays, G.C., Meekan, M.G., Thums, M., Irigoien, X., Eguiluz, V.M., Duarte, C.M., Sousa, L.L., Simpson, S.J., Southall, E.J., Sims, D.W., Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., da Costa, I., Sequeira, A.M.M., Mucientes, G., Santos, A.M., Abascal, F.J., Abercrombie, D.L., Abrantes, K., Acuña-Marrero, D., Afonso, A.S., Afonso, P., Anders, D., Araujo, G., Arauz, R., Bach, P., Barnett, A., Bernal, D., Berumen, M.L., Lion, S.B., Bezerra, N.P.A., Blaison, A.V., Block, B.A., Bond, M.E., Bonfil, R., Braun, C.D., Brooks, E.J., Brooks, A., Brown, J., Byrne, M.E., Campana, S.E., Carlisle, A.B., Chapman, D.D., Chapple, T.K., Chisholm, J., Clarke, C.R., Clua, E.G., Cochran, J.E.M., Crochelet, E.C., Dagorn, L., Daly, R., Cortés, D.D., Doyle, T.K., Drew, M., Duffy, C.A.J., Erikson, T., Espinoza, E., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Fischer, G.C., Fitzpatrick, R., Fontes, J., Forget, F., Fowler, M., Francis, M.P., Gallagher, A.J., Gennari, E., Goldsworthy, S.D., Gollock, M.J., Green, J.R., Gustafson, J.A., Guttridge, T.L., Guzman, H.M., Hammerschlag, N., Harman, L., Hazin, F. H.V., Heard, M., Hearn, A.R., Holdsworth, J.C., Holmes, B.J., Howey, L.A., Hoyos, M., Hueter, R.E., Hussey, N.E., Huveneers, C., Irion, D.T., Jacoby, D.M.P., Jewell, O.J.D., Johnson, R., Jordan, L.K.B., Joyce, W., Keating Daly, C.A., Ketchum, J.T., Klimley, A.P., Kock, A.A., Koen, P., Ladino, F., Lana, F.O., Lea, J.S.E., Llewellyn, F., Lyon, W.S., MacDonnell, A., Macena, B.C.L., Marshall, H., McAllister, J.D., Meÿer, M.A., Morris, J.J., Nelson, E.R., Papastamatiou, Y.P., Peñaherrera-Palma, C., Pierce, S.J., Poisson, F., Quintero, L.M., Richardson, A.J., Rogers, P.J., Rohner, C.A., Rowat, D.R.L., Samoilys, M., Semmens, J.M., Sheaves, M., Shillinger, G., Shivji, M., Singh, S., Skomal, G.B., Smale, M.J., Snyders, L.B., Soler, G., Soria, M., Stehfest, K.M., Thorrold, S.R., Tolotti, M.T., Towner, A., Travassos, P., Tyminski, J.P., Vandeperre, F., Vaudo, J.J., Watanabe, Y.Y., Weber, S.B., Wetherbee, B.M., White, T.D., Williams, S., Zárate, P.M., Harcourt, R., Hays, G.C., Meekan, M.G., Thums, M., Irigoien, X., Eguiluz, V.M., Duarte, C.M., Sousa, L.L., Simpson, S.J., Southall, E.J., and Sims, D.W.

Abstract

Our global analysis1 estimated the overlap and fishing exposure risk (FEI) using the space use of satellite-tracked sharks and longline fishing effort monitored by the automatic identification system (AIS)...

Published
2021

10. Recent expansion of marine protected areas matches with home range of grey reef sharks

Author

Bonnin, L, Mouillot, D, Boussarie, G, Robbins, WD, Kiszka, JJ, Dagorn, L, Vigliola, L, Bonnin, L, Mouillot, D, Boussarie, G, Robbins, WD, Kiszka, JJ, Dagorn, L, and Vigliola, L

Abstract

Dramatic declines in reef shark populations have been documented worldwide in response to human activities. Marine Protected Areas (MPAs) offer a useful mechanism to protect these species and their roles in coral reef ecosystems. The effectiveness of MPAs notably relies on compliance together with sufficient size to encompass animal home range. Here, we measured home range of 147 grey reef sharks, Carcharhinus amblyrhynchos, using acoustic telemetry in New Caledonia. The distribution of home range was then compared to local MPA sizes. We report a home range of 12 km2 of reef for the species with strong differences between adult males (21 km2), adult females (4.4 km2) and juveniles (6.2 km2 for males, 2.7 km2 for females). Whereas local historic MPA size seemed adequate to protect reef shark home range in general, these were clearly too small when considering adult males only, which is consistent with the reported failure of MPAs to protect sharks in New Caledonia. Fortunately, the recent implementation of several orders of magnitude larger MPAs in New Caledonia and abroad show that recent Indo-Pacific MPAs are now sufficiently large to protect the home ranges of this species, including males, across its geographical range. However, protection efforts are concentrated in a few regions and cannot provide adequate protection at a global scale.

Published
2021

11. Silky Shark Population Trend In The Indian Ocean Derived From Its Associative Behavior With Floating Objects

Author

Diallo, A, Travassos Tolotti, Mariana, Sabarros, Philippe S.S., Dagorn, L., Deneubourg, J.L., Murua, Hilario, Ruiz, J., Ramos, María LourdesL., Báez, José CarlosC., Abascal, Francisco JavierJ., Pascual-Alayón, Pedro JoséJ., and Capello, M.

Subjects
Centro Oceanográfico de Canarias
Abstract

Silky sharks (Carcharhinus falciformis) figure among the main pelagic shark species caught by the industrial tropical tuna purse-seine fisheries. However, this data was not used so far for estimating their population trends. In this study, using data from the European tropical tuna purse seine fishery, we provide an abundance trend for the silky shark, based on the associative behavior of this species with floating objects (FOBs). Two models were used, describing the dynamics of sharks associated to floating objects (FOBs) in a social and in a non-social case. The parameters estimates of the models were obtained by fitting the distribution of the number of sharks caught per set. The relative abundance indices were derived for the Seychelles area and the Mozambique Channel. For both areas, an upward trend was observed. In the Seychelles area, the abundance index increased by a factor of 3 from 2006 to 2018 and in the Mozambique Channel the increase reached a factor of 15. This modeling approach could be extended to other bycatch species to generate population trends and could be useful for future stock assessment analyses.

Published
2019

12. Preliminary results of BIOFAD project: testing designs and identifying options to mitigate impacts of drifting Fish Aggregating Devices on the ecosystem

Author

Zudaire, I., Tolotti, M., Murua, J., Capello, M., Andrés, M., Cabezas, O., Krug, I., Grande, M., Arregui, I., Uranga, J., Goñi, Nicolás, Ferarios, J.M., Ruiz, J., Baidai, Y., Sabarros, P.S., Ramos, María Lourdes, Báez, José Carlos, Abascal, Francisco Javier, Moreno, Gala, Santiago, J., Dagorn, L., Arrizabalaga, Haritz, and Murua, Hilario

Subjects
purse seiner, FADs, biodegradable materials, Centro Oceanográfico de Canarias, Pesquerías, tropical tuna
Abstract

The EU project BIOFAD was launched in August 2017. This 28-months EU project is coordinated by a Consortium comprising three European research centers: AZTI, IRD (Institut de recherche pour le développement) and IEO (Instituto Español de Oceanografía). The International Seafood Sustainability Foundation (ISSF) is also actively collaborating by providing the biodegradable materials needed to test biodegradable dFADs (drifting FADs). Following IOTC, along with other tuna RFMOs, recommendations and resolutions to promote the use of natural or biodegradable materials for dFADs, this project is seeking to develop and implement the use of dFADs with both characteristics, non-entangling and biodegradable, in the IOTC Convention Area. However, there are no technical guidelines on the type of materials and FAD designs to be used. The main objectives of the project are: (1) to test the use of specific biodegradable materials and designs for the construction of dFADs in real fishing conditions; (2) to identify options to mitigate dFADs impacts on the ecosystem; and (3) to assess the socio-economic viability of the use of biodegradable dFADs in the purse seine tropical tuna fishery. This document shows the preliminary results regarding the effectiveness of around 716 BIOFADs deployed, in terms of tuna aggregation, drift, materials’ durability, etc. in comparison to currently deployed NEFADs (non-entangling dFADs). The project BIOFAD has counted since its inception with the support of the whole EU purse seine tuna fishery and, more recently, with the collaboration of the Korean purse seine fleet.

Published
2019

13. Results of the BIOFAD Project: Testing Designs and Identify Options to Mitigate Impacts of Drifting Fish Aggregating Devices on the Ecosystem

Author

Zudaire, I., Tolotti, M., Murua, J., Capello, M., Andrés, M., Cabezas, O., Krug, I., Grande, M., Arregui, I., Uranga, J., Goñi, Nicolás, Sabarros, P.S., Ferarios, J.M., Ruiz, J., Baidai, Y., Ramos, María Lourdes, Báez, José Carlos, Abascal, Francisco Javier, Moreno, Gala, Santiago, J., Dagorn, L., Arrizabalaga, Haritz, and Murua, Hilario

Subjects
Centro Oceanográfico de Málaga, Pesquerías
Abstract

The EU project BIOFAD was launched in August 2017. This 28-months EU project is coordinated by a Consortium comprising three European research centers: AZTI, IRD (Institut de recherche pour le développement) and IEO (Instituto Español de Oceanografía). The International Seafood Sustainability Foundation (ISSF) is also actively collaborating by providing the biodegradable materials needed to test biodegradable dFADs (drifting FADs). Following IOTC, along with other tuna RFMOs, recommendations and resolutions to promote the use of natural or biodegradable materials for dFADs, this project is seeking to develop and implement the use of dFADs with both characteristics, non-entangling and biodegradable, in the IOTC Convention Area. However, there are no technical guidelines on the type of materials and FAD designs to be used. The main objectives of the project are: (1) to test the use of specific biodegradable materials and designs for the construction of dFADs in real fishing conditions; (2) to identify options to mitigate dFADs impacts on the ecosystem; and (3) to assess the socioeconomic viability of the use of biodegradable dFADs in the purse seine tropical tuna fishery. This document shows the results regarding the effectiveness of 771 BIOFADs deployed within the project, in terms of FAD lifespan, drift, materials’ durability, catch and tuna aggregation in comparison to currently deployed NEFADs (non-entangling dFADs). The project BIOFAD has been supported since its inception by the whole EU purse seine tuna fishery and, more recently, with the collaboration of the Korean purse seine fleet.

Published
2019

14. Global spatial risk assessment of sharks under the footprint of fisheries

Author

Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., da Costa, I., Sequeira, A.M.M., Mucientes, G., Santos, A.M., Abascal, F.J., Abercrombie, D.L., Abrantes, K., Acuña-Marrero, D., Afonso, A.S., Afonso, P., Anders, D., Araujo, G., Arauz, R., Bach, P., Barnett, A., Bernal, D., Berumen, M.L., Bessudo Lion, S., Bezerra, N.P.A., Blaison, A.V., Block, B.A., Bond, M.E., Bonfil, R., Bradford, R.W., Braun, C.D., Brooks, E.J., Brooks, A., Brown, J., Bruce, B.D., Byrne, M.E., Campana, S.E., Carlisle, A.B., Chapman, D.D., Chapple, T.K., Chisholm, J., Clarke, C.R., Clua, E.G., Cochran, J.E.M., Crochelet, E.C., Dagorn, L., Daly, R., Cortés, D.D., Doyle, T.K., Drew, M., Duffy, C.A.J., Erikson, T., Espinoza, E., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Fischer, G.C., Fitzpatrick, R., Fontes, J., Forget, F., Fowler, M., Francis, M.P., Gallagher, A.J., Gennari, E., Goldsworthy, S.D., Gollock, M.J., Green, J.R., Gustafson, J.A., Guttridge, T.L., Guzman, H.M., Hammerschlag, N., Harman, L., Hazin, F.H.V., Heard, M., Hearn, A.R., Holdsworth, J.C., Holmes, B.J., Howey, L.A., Hoyos, M., Hueter, R.E., Hussey, N.E., Huveneers, C., Irion, D.T., Jacoby, D.M.P., Jewell, O.J.D., Johnson, R., Jordan, L.K.B., Jorgensen, S.J., Joyce, W., Keating Daly, C.A., Ketchum, J.T., Klimley, A.P., Kock, A.A., Koen, P., Ladino, F., Lana, F.O., Lea, J.S.E., Llewellyn, F., Lyon, W.S., MacDonnell, A., Macena, B.C.L., Marshall, H., McAllister, J.D., McAuley, R., Meÿer, M.A., Morris, J.J., Nelson, E.R., Papastamatiou, Y.P., Patterson, T.A., Peñaherrera-Palma, C., Pepperell, J.G., Pierce, S.J., Poisson, F., Quintero, L.M., Richardson, A.J., Rogers, P.J., Rohner, C.A., Rowat, D.R.L., Samoilys, M., Semmens, J.M., Sheaves, M., Shillinger, G., Shivji, M., Singh, S., Skomal, G.B., Smale, M.J., Snyders, L.B., Soler, G., Soria, M., Stehfest, K.M., Stevens, J.D., Thorrold, S.R., Tolotti, M.T., Towner, A., Travassos, P., Tyminski, J.P., Vandeperre, F., Vaudo, J.J., Watanabe, Y.Y., Weber, S.B., Wetherbee, B.M., White, T.D., Williams, S., Zárate, P.M., Harcourt, R., Hays, G.C., Meekan, M.G., Thums, M., Irigoien, X., Eguíluz, V.M., Duarte, C.M., Sousa, L.L., Simpson, S.J., Southall, E.J., Sims, D.W., Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., da Costa, I., Sequeira, A.M.M., Mucientes, G., Santos, A.M., Abascal, F.J., Abercrombie, D.L., Abrantes, K., Acuña-Marrero, D., Afonso, A.S., Afonso, P., Anders, D., Araujo, G., Arauz, R., Bach, P., Barnett, A., Bernal, D., Berumen, M.L., Bessudo Lion, S., Bezerra, N.P.A., Blaison, A.V., Block, B.A., Bond, M.E., Bonfil, R., Bradford, R.W., Braun, C.D., Brooks, E.J., Brooks, A., Brown, J., Bruce, B.D., Byrne, M.E., Campana, S.E., Carlisle, A.B., Chapman, D.D., Chapple, T.K., Chisholm, J., Clarke, C.R., Clua, E.G., Cochran, J.E.M., Crochelet, E.C., Dagorn, L., Daly, R., Cortés, D.D., Doyle, T.K., Drew, M., Duffy, C.A.J., Erikson, T., Espinoza, E., Ferreira, L.C., Ferretti, F., Filmalter, J.D., Fischer, G.C., Fitzpatrick, R., Fontes, J., Forget, F., Fowler, M., Francis, M.P., Gallagher, A.J., Gennari, E., Goldsworthy, S.D., Gollock, M.J., Green, J.R., Gustafson, J.A., Guttridge, T.L., Guzman, H.M., Hammerschlag, N., Harman, L., Hazin, F.H.V., Heard, M., Hearn, A.R., Holdsworth, J.C., Holmes, B.J., Howey, L.A., Hoyos, M., Hueter, R.E., Hussey, N.E., Huveneers, C., Irion, D.T., Jacoby, D.M.P., Jewell, O.J.D., Johnson, R., Jordan, L.K.B., Jorgensen, S.J., Joyce, W., Keating Daly, C.A., Ketchum, J.T., Klimley, A.P., Kock, A.A., Koen, P., Ladino, F., Lana, F.O., Lea, J.S.E., Llewellyn, F., Lyon, W.S., MacDonnell, A., Macena, B.C.L., Marshall, H., McAllister, J.D., McAuley, R., Meÿer, M.A., Morris, J.J., Nelson, E.R., Papastamatiou, Y.P., Patterson, T.A., Peñaherrera-Palma, C., Pepperell, J.G., Pierce, S.J., Poisson, F., Quintero, L.M., Richardson, A.J., Rogers, P.J., Rohner, C.A., Rowat, D.R.L., Samoilys, M., Semmens, J.M., Sheaves, M., Shillinger, G., Shivji, M., Singh, S., Skomal, G.B., Smale, M.J., Snyders, L.B., Soler, G., Soria, M., Stehfest, K.M., Stevens, J.D., Thorrold, S.R., Tolotti, M.T., Towner, A., Travassos, P., Tyminski, J.P., Vandeperre, F., Vaudo, J.J., Watanabe, Y.Y., Weber, S.B., Wetherbee, B.M., White, T.D., Williams, S., Zárate, P.M., Harcourt, R., Hays, G.C., Meekan, M.G., Thums, M., Irigoien, X., Eguíluz, V.M., Duarte, C.M., Sousa, L.L., Simpson, S.J., Southall, E.J., and Sims, D.W.

Abstract

Brucellosis is a highly contagious zoonosis affecting humans and a wide range of domesticated and wild animal species. An important element for effective disease containment is to improve knowledge, attitudes and practices (KAP) of afflicted communities. This study aimed to assess the KAP related to brucellosis at the human–animal interface in an endemic area of Egypt and to identify the risk factors for human infection. A matched case–control study was conducted at the central fever hospitals located in six governorates in northern Egypt. Face‐to‐face interviews with cases and controls were conducted using a structured questionnaire. In total, 40.7% of the participants owned farm animals in their households. The overall mean practice score regarding animal husbandry, processing and consumption of milk and dairy products were significantly lower among cases compared with controls (−12.7 ± 18.1 vs. 0.68 ± 14.2, respectively; p < .001). Perceived barriers for notification of animal infection/abortion were predominate among cases and positively correlated with participants’ education. The predictors of having brucellosis infection were consumption of unpasteurized milk or raw dairy products and practicing animal husbandry. Applying protective measures against infection significantly reduced its risk. A model predicting risk factors for brucellosis among those who own animal showed that frequent abortions per animal increased the chance for brucellosis infection among human cases by 50‐fold (95% CI: 8.8–276.9), whereas the use of protective measures in animal care reduced the odds (OR = 0.11 [95% CI: 0.03–0.45]). In conclusion, consumption of unprocessed dairy products was equally important as contact with infected/aborted animals as major risk factors for Brucella spp. infection among humans in Egypt. There is poor knowledge, negative attitudes and risky behaviours among villagers which can perpetuate the risk of brucellosis transmission at the human–animal interface.

Published
2019

15. Repeated long-range migrations of adult males in a common Indo-Pacific reef shark

Author

Bonnin, L, Robbins, WD, Boussarie, G, Kiszka, JJ, Dagorn, L, Mouillot, D, Vigliola, L, Bonnin, L, Robbins, WD, Boussarie, G, Kiszka, JJ, Dagorn, L, Mouillot, D, and Vigliola, L

Abstract

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. The grey reef shark, Carcharhinus amblyrhynchos, is one of the most abundant coral reef sharks throughout the Indo-Pacific. However, this species has been critically impacted across its range, with well-documented population declines of > 90% attributed to human activities. A key knowledge gap in the successful implementation of grey reef shark conservation plans is the understanding of large-scale movement patterns, along with the associated biological and ecological drivers. To address this shortfall, we acoustically monitored 147 adult and juvenile grey reef sharks of all sexes for more than 2 yr across the New Caledonian archipelago, West Pacific. Here, we document multiple adult males undertaking return journeys of up to nearly 700 km in consecutive years. This constitutes the first evidence of repeated long-range migrations for this species. Although only a limited number of adult males were definitively tracked undertaking migrations, similar timing in changes in the detection patterns of a further 13 animals, mostly adult males, suggests this behavior may be more common than previously thought. The paucity of evidence for juvenile migrations and timing of adult movements suggest that mating is the motivation behind these migrations. Our results have important implications for management, given the potential of mature individuals to recurrently travel outside managed or protected areas. Future management of this species clearly needs to consider the importance of large-scale migratory behaviors when developing management plans.

Published
2019

17. Balanced Harvest in the Real World. Scientific, Policy and Operational Issues in an Ecosystem Approach to Fisheries

Author

Garcia, S.M., Bianchi, G., Charles, A., Kolding, J., Rice, J., Rochet, M.J., Zhou, S., Delius, G., Reid, D., van Zwieten, P.A.M., Atcheson, M., Bartley, D., Borges, L., Bundy, A., Dagorn, L., Dunn, D., Hall, M., Heino, M., Jacobsen, B., Jacobsen, N.S., Law, R., Makino, M., Martin, F., Skern-Mauritzen, M., Suuronen, P., and Symons, D.

Subjects
Aquaculture and Fisheries, Aquacultuur en Visserij, WIAS, Life Science, Wageningen Marine Research
Abstract

The concept of the Ecosystem Approach has entered the fishery harvesting discussions both from fishery perspectives (Reykjavik Declaration; FAO 2003 Annex to the Code of Conduct and from the principles of the Ecosystem Approach adopted by the CBD in 1995. Both perspectives establish the need to maintain ecosystem structure and functioning, whether for sustainable use of biodiversity (CBD) or simply to keep exploited ecosystems healthy and productive (fisheries). In response, the “Balanced Harvest” (BH) concept was suggested by a group of scientists brought together by the IUCN Fisheries Experts Group during the CBD CoP 10 in 2010. The meeting and the BH concept as consolidated there highlighted some of the collateral ecological effects of current fishing patterns and unbalanced removals of particular components of the food web, stimulating a critical rethinking of current approaches to fisheries management. The meeting on “Balanced Harvest in the real world - Scientific, policy and operational issues in an ecosystem approach to fisheries” (Rome, September 29-October 2, 2014) examined the progress made since 2010 on a number of fronts. It considered questions related to the scientific underpinning of the BH concept, including theory, modelling, and empirical observations. It began to explore the economic, policy and management implications of harvesting in a more balanced way.

Published
2015

18. Population assessment of tropical tuna based on their associative behavior around floating objects

Author

Capello, M., Deneubourg, J. L., Robert, Marianne, Holland, K. N., Schaefer, K. M., Dagorn, L., Capello, M., Deneubourg, J. L., Robert, Marianne, Holland, K. N., Schaefer, K. M., and Dagorn, L.

Abstract

Estimating the abundance of pelagic fish species is a challenging task, due to their vast and remote habitat. Despite the development of satellite, archival and acoustic tagging techniques that allow the tracking of marine animals in their natural environments, these technologies have so far been underutilized in developing abundance estimations. We developed a new method for estimating the abundance of tropical tuna that employs these technologies and exploits the aggregative behavior of tuna around floating objects (FADs). We provided estimates of abundance indices based on a simulated set of tagged fish and studied the sensitivity of our method to different association dynamics, FAD numbers, population sizes and heterogeneities of the FAD-array. Taking the case study of yellowfin tuna (Thunnus albacares) acoustically-tagged in Hawaii, we implemented our approach on field data and derived for the first time the ratio between the associated and the total population. With more extensive and long-term monitoring of FAD-associated tunas and good estimates of the numbers of fish at FADs, our method could provide fisheries-independent estimates of populations of tropical tuna. The same approach can be applied to obtain population assessments for any marine and terrestrial species that display associative behavior and from which behavioral data have been acquired using acoustic, archival or satellite tags.

Published
2016
Full Text
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20. Targeting bigger schools can reduce ecosystem impacts of fisheries

Author

Dagorn, L., Filmalter, J.D., Forget, F., Amandè, M.J. (Monin J.), Hall, M., Williams, P., Murua, H. (Hilario), Ariz-Tellería, F.J. (Francisco Javier), Chavance, P., and Bez, N.

Subjects
RENDEMENT, IMPACT DE LA PECHE, APPROCHE ECOSYSTEMIQUE, DISPOSITIF DE CONCENTRATION DES POISSONS, GESTION DES PECHES, PRISE ACCESSOIRE, Centro Oceanográfico de Canarias, ANALYSE QUANTITATIVE, Pesquerías, PECHE THONIERE, MARQUAGE
Abstract

Sí

Published
2012

23. Modeling tuna behaviour near floating objects : from individuals to aggregations

Author

Dagorn, L., Josse, E., Bach, P., and Arnaud Bertrand

Subjects
FLOTTEUR, REPARTITION VERTICALE, BANC DE POISSONS, DISPOSITIF DE CONCENTRATION DES POISSONS, THON, REPARTITION HORIZONTALE, COMPORTEMENT ALIMENTAIRE, DYNAMIQUE DE POPULATION, CAPTEUR, TELEMETRIE ULTRASONIQUE, LOGIQUE FLOUE, DISTRIBUTION SPATIALE, MODELISATION
Abstract

Un modèle de logique floue du comportement des thons autour de dispositifs de concentration de poissons (DCP) est développé pour reproduire les différences individuelles observées dans les mouvements horizontaux à partir d'expériences de télémétrie ultrasonique. Dans ce modèle, le comportement d'un individu est basé sur son environnement local (DCP et proies) et sur son état interne (taux de remplissage de l'estomac), qui dépend de ses actions passées. Des capteurs internes déterminent la motivation du poisson, qui, combinée avec des capteurs externes, détermine ses mouvements. Les informations sensorielles et la motivation sont modélisées avec des ensembles flous. Un individu est toujours attiré par un DCP s'il se trouve dans un certain rayon autour de celui-ci. Le temps passé autour d'un DCP dépend de la motivation alimentaire du poisson et de son environnement local. Si le poisson n'a pas faim, il reste autour du DCP. Sinon, le poisson doit rechercher de la nourriture, et peut ainsi quitter le DCP s'il ne trouve pas de proies aux alentours. En variant les conditions environnementales autour du DCP, ce modèle reproduit les différents mouvements horizontaux observés chez les thons. Le modèle est ensuite étendu pour permettre la coexistence de plusieurs individus, sans aucune interaction directe ou indirecte entre ceux-ci. Ceci permet d'étudier les effets des comportements individuels sur les agrégations de thons autour de DCP. Le modèle prédit avec précision les dynamiques temporelles des agrégations de thons autour de DCP. En simulant différents réseaux de DCP, le modèle permet d'estimer la meilleure organisation spatiale des DCP. (Résumé d'auteur)

Published
2000

25. Quantifying the interplay between environmental and social effects on aggregated-fish dynamics

Author

Capello, Manuela, Soria, M, Cotel, Pascal, Deneubourg, Jean-Louis, Dagorn, L., Capello, Manuela, Soria, M, Cotel, Pascal, Deneubourg, Jean-Louis, and Dagorn, L.

Abstract

Demonstrating and quantifying the respective roles of social interactions and external stimuli governing fish dynamics is key to understanding fish spatial distribution. If seminal studies have contributed to our understanding of fish spatial organization in schools, little experimental information is available on fish in their natural environment, where aggregations often occur in the presence of spatial heterogeneities. Here, we applied novel modeling approaches coupled to accurate acoustic tracking for studying the dynamics of a group of gregarious fish in a heterogeneous environment. To this purpose, we acoustically tracked with submeter resolution the positions of twelve small pelagic fish (Selar crumenophthalmus) in the presence of an anchored floating object, constituting a point of attraction for several fish species. We constructed a field-based model for aggregated-fish dynamics, deriving effective interactions for both social and external stimuli from experiments. We tuned the model parameters that best fit the experimental data and quantified the importance of social interactions in the aggregation, providing an explanation for the spatial structure of fish aggregations found around floating objects. Our results can be generalized to other gregarious species and contexts as long as it is possible to observe the fine-scale movements of a subset of individuals. © 2011 Capello et al., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2011

26. Visual censuses around drifting fish aggregating devices (FADs): a new approach for assessing the diversity of fish in open-ocean waters

Author

Gaertner, J, Taquet, Marc, Dagorn, L, Merigot, B, Aumeeruddy, R, Sancho, G, Itano, D, Gaertner, J, Taquet, Marc, Dagorn, L, Merigot, B, Aumeeruddy, R, Sancho, G, and Itano, D

Abstract

This study provides a baseline measure of pelagic fish species diversity around fish aggregating devices (FADs) in the Western Indian Ocean. Using data from visual censuses made by SCUBA divers around drifting FADs we (1) analysed 11 diversity indices describing 4 main components of pelagic diversity: number of species, evenness, taxonomic diversity and rarity and (2) discussed the viability of using visual censuses around FADs to monitor temporal and spatial changes in diversity patterns of pelagic fishes in the future. Our results not only show that a single index, such as species richness or the Shannon-Wiener index, cannot provide a complete description of pelagic fish diversity around FADs, but also that some components of diversity appear to be multifaceted themselves and require the simultaneous use of several complementary indices in order to be accurately described and monitored. Despite a limited sampling effort, our results suggest that using visual censuses around FADs could provide reproducible 'relative' indices of diversity for a well-delimited assemblage of species (intra- and extranatant species in the epipelagic domain). In this context, we propose a preliminary 'short list' of diversity indices based firstly on their complementarity and secondly on their simplicity. While visual censuses of pelagic fishes at FADs (like any other sampling method) cannot give an exhaustive picture of diversity, they are a fishery-independent survey method that can complement other sampling techniques and provide reproducible information to monitor the diversity of these very difficult-to-access pelagic fish communities.

Published
2008
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29. Characterizing fish communities associated with drifting fish aggregating devices (FADs) in the Western Indian Ocean using underwater visual surveys

Author

Taquet, Marc, Sancho, G, Dagorn, L, Gaertner, J, Itano, D, Aumeeruddy, R, Wendling, B, Peignon, C, Taquet, Marc, Sancho, G, Dagorn, L, Gaertner, J, Itano, D, Aumeeruddy, R, Wendling, B, and Peignon, C

Abstract

We adapted a visual census method, mainly used in demersal and reef fish studies, to characterize fish communities associated to drifting fish aggregating devices (FADs) in the Western Indian Ocean. Drifting FAD associated fishes from both equatorial (Seychelles) and tropical waters (Reunion Island) were examined by divers. A total of 32 species (belonging to 16 families) were observed associated with drifting FADs in equatorial waters, and 24 species (14 families) were found around FADs in tropical waters. Twenty species were found in both regions. The highest number of species observed at a single FAD was 18 (12 +/- 2, mean +/- SD) in equatorial and 13 (10 +/- 3) in tropical waters, not counting circumnatant species loosely associated with the FAD. Some species like Kyphosus vaigiensis, Canthidermis maculata, Elagatis bipinnulata, Acanthocybium solandri and Coryphaena hippurus were observed on all or most of the surveys. In this study, the contribution in biomass of the 18 common species associated with drifting FADs (but excluding circumnatant species), represents more than 98% of the biomass. The overall biomass values of closely associated species remains well below tuna biomass estimates for circumnatant tuna schools at FADs, estimated as high as 200 tons. The species that most significantly contribute to the by-catch in tuna purse-seines logically match those that showing the highest biomass values in our surveys (Carcharhinus spp., Elagatis bipinnulata, Coryphaena hippurus, Canthidermis maculata, and Acanthocybium solandri). One of the most abundant and ubiquitous species in our study was the spotted oceanic triggerfish Canthidermis maculata that sometimes formed massive schools of many thousands individuals around the drifting FADs. Future research is needed to explore the role of such non tuna species in the attraction and aggregation processes of tuna around drifting FADs.

Published
2007

30. Satellite-linked acoustic receivers to observe behavior of fish in remote areas

Author

Dagorn, L, Pincock, D, Girard, C, Holland, K, Taquet, Marc, Sancho, G, Itano, D, Aumeeruddy, R, Dagorn, L, Pincock, D, Girard, C, Holland, K, Taquet, Marc, Sancho, G, Itano, D, and Aumeeruddy, R

Abstract

Automated acoustic receivers are now widely used by biologists to study the behavior of fish. However, currently available acoustic receivers require physical recovery of the units to download stored data. Such operation is often difficult in remote study areas like in the open ocean. We present a new satellite-linked acoustic receiver (Vemco VR3-Argos) that allows downloading data through a satellite uplink (Argos). The VR3-Argos can last up to one year, sending GPS positions and tag data at regular time intervals. We illustrate the advantages of this new technology with tagging data from 121 fish of seven species (yellowfin tuna, bigeye tuna, skipjack tuna, wahoo, dolphinfish, silky shark and oceanic triggerfish) caught and released around drifting fish aggregating devices (FADs) in the Western Indian Ocean, far from any land. In opposition with the classic acoustic receivers (Vemco VR2), the use of VR3-Argos allowed to collect data for several weeks after leaving the drifting FADs. Maximum residence times of 3 days for bigeye tuna, 7 days for skipjack, 8 days for wahoo, 10 days for silky shark and 15 days for yellowfin tuna, dolphinfish and oceanic triggerfish could be recorded. VR2 and VR3-Argos are equivalent in terms of quality of residence times data, however depth data obtained through satellites are aggregated in 8 classes for compression purposes, which leads to a loss of precision available with raw data. Future directions of this technology are discussed.

Published
2007
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31. Behavior of dolphinfish (Coryphaena hippurus) around drifting FADs as observed from automated acoustic receivers

Author

Taquet, Marc, Dagorn, L, Gaertner, J, Girard, C, Aumerruddy, R, Sancho, G, Itano, D, Taquet, Marc, Dagorn, L, Gaertner, J, Girard, C, Aumerruddy, R, Sancho, G, and Itano, D

Abstract

To study the behavior of dolphinfish (Coryphaena hippurus) around drifting Fish Aggregating Devices (FADs), we tagged individuals with long-lived, coded sonic transmitters and attached automated sonic receivers to drifting FADs in two regions of the Western Indian Ocean. Among the three tagging methods used in this study (surgery, external hooks, underwater bait without capture), the latest resulted in residence times significantly shorter than the other ones, likely due to regurgitation. Dolphinfish tagged with the two other methods usually stayed several days associated to FADs (Kaplan-Meier survival analysis 5.09 days, mean 6.25 days, SD 4.39 days, maximum 15.26 days), drifting with them. There was no significant difference in the residence times of dolphinfish in equatorial and tropical areas. While associated to FADs, dolphinfish spent most of their time close to floating object (< 365 m). The total time spent away from FADs was low (median 8%), and likely corresponded to making feeding excursions. Dolphinfish did not form a single school while associated to a given FADs, but formed multiple small schools. FADs are likely to be sites with exchanges of individuals between schools. These results are discussed in regards to the possibility of FADs acting as ecological traps and the validity of meeting-point hypotheses as an explanation for fish aggregations under floating objects.

Published
2007
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32. Homing abilities of dolphinfish (Coryphaena hippurus) displaced from fish aggregating devices (FADs) determined using ultrasonic telemetry

Author

Girard, C, Dagorn, L, Taquet, Marc, Aumeeruddy, R, Peignon, C, Benhamou, S, Girard, C, Dagorn, L, Taquet, Marc, Aumeeruddy, R, Peignon, C, and Benhamou, S

Abstract

We conducted displacement experiments using acoustic tags to study the orientation abilities of dolphinfish (Coryphaena hippurus) around FADs. Eleven fish were passively monitored using coded transmitters and acoustic receivers attached to FADs, while seven others were actively tracked with a vessel using continuous acoustic tags equipped with pressure sensors. All these 18 dolphinfish were captured close to a FAD and released between 70 and 1720 m from it. Five fish out of the 14 that were displaced at more than 360 m from a FAD ( estimated detection range of our acoustic receivers, defining the target area during our experiment) returned to the target area. With one individual successfully returning to the target area after having been released at 1600 m from the FAD, the rate of return of fish released up to this distance was significantly higher than expected if they were moving at random, but many fish released at intermediate distances moved in other directions. Based on detailed statistical analysis of the return score, we estimated that dolphinfish are able to orientate towards a FAD area from at least 820 m. The connection between our definition of the target area and the association area of dolphinfish around a FAD is discussed, as well as the impact of stress and motivation in the rates of return observed. More experiments should be conducted to improve this first estimate. Specific experiments should also be designed to more accurately determine the association range of fish around FADs and their motivation to orientate towards FADs.

Published
2007
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33. Foraging of the green sea turtle Chelonia mydas on seagrass beds at Mayotte Island (Indian Ocean), determined by acoustic transmitters

Author

Taquet, Coralie, Taquet, Marc, Dempster, T, Soria, M, Ciccione, S, Roos, David, Dagorn, L, Taquet, Coralie, Taquet, Marc, Dempster, T, Soria, M, Ciccione, S, Roos, David, and Dagorn, L

Abstract

We studied the foraging rhythms of green sea turtles Chelonia mydas on the seagrass beds of N'Gouja Bay, Mayotte Island (Comoros Archipelago) with acoustic transmitters and moored listening stations. We monitored 8 tagged turtles (4 probable males, 3 probable females and 1 immature), from 70 to 109 cm curved carapace length (CCL), for durations ranging from 5 to 92 d. The turtles exhibited a regular diel pattern: they foraged mainly during the day (on average 87% of seagrass detections were between 06:00 and 18:00 h) and rested on the inner reef slope during the night. Night time feeding activities were observed on the seagrass bed when the night light was high. The presence of turtles on the seagrass bed at night was significantly correlated with a night light index (r = 0.54, p = 0.002), which included both moon light and cloudiness indices. Behaviour of the only immature individual observed was similar to adult turtles, although it rested more frequently around noon. All turtles displayed a high fidelity to 1 foraging site within the seagrass bed. Acoustic transmitters and permanent listening stations are an appropriate technique for long-term behavioural studies of turtles, with no human interaction with turtles during tracking, and represent a suitable technique to assess the possible effects of environmental changes or human activities upon green turtle behaviour.

Published
2006
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40. Quantifying the impact of habitat modifications on species behavior and mortality: A case study of tropical tuna.

Author

Dupaix A, Dagorn L, Deneubourg JL, and Capello M

Subjects
Animals, Fisheries, Behavior, Animal, Conservation of Natural Resources, Indian Ocean, Tuna physiology, Ecosystem
Abstract

Ecosystems and biodiversity across the world are being altered by human activities. Habitat modification and degradation are among the most important drivers of biodiversity loss. These modifications can have an impact on species behavior, which can, in turn, impact their mortality. While several studies have investigated the impacts of habitat degradation and fragmentation on terrestrial species, the extent to which habitat modifications affect the behavior and fitness of marine species is still largely unknown, particularly for pelagic species. Since the early 1990s, industrial purse seine vessels targeting tuna have started deploying artificial floating objects-Drifting Fish Aggregating Devices (DFADs)-in all oceans to increase tuna catchability. Since then, the massive deployment of DFADs has modified tuna surface habitat, by increasing the density of floating objects, with potential impacts on tuna associative behavior and mortality. In this study, we investigate these impacts for yellowfin tuna in the Indian Ocean. Using an individual-based model based on a correlated random walk and newly available data on DFAD densities, we quantify for the first time how the increase in floating object density, due to DFAD use, affects the percentage of time that yellowfin tuna spend associated, which, in turn, directly impacts their availability to fishers and fishing mortality. This modification of tuna associative behavior could also have indirect impacts on their fitness, by retaining tuna in areas detrimental to them or disrupting schooling behavior. Hence, there is an urgent need to further investigate DFAD impacts on tuna behavior, in particular, taking social behavior into account, and to continue regulation efforts on DFAD use and monitoring., (© 2024 The Author(s). Ecological Applications published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

Published
2024
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41. How technical change has boosted fish aggregation device productivity in the Indian Ocean tuna fishery.

Author

Tidd AN, Floc'h L, Imzilen T, Tolotti M, Dagorn L, Capello M, and Guillotreau P

Subjects
Animals, Fisheries, Indian Ocean, Pacific Ocean, Tuna, Conservation of Natural Resources
Abstract

Excess harvesting power can threaten the long-term sustainability of fisheries. Indicators of excess harvesting capacity must include input-output-based estimates of economic production efficiency. The increasing use of drifting Fish-Aggregating-Devices (DFADs) has boosted fishing productivity in high-seas tuna fisheries, perhaps beyond the biological capacity of the stocks, and is an object of global debate. We carried out a Data Envelopment Analysis (DEA) of relative changes in production efficiencies of the French purse-seine fleet targeting tropical tuna in the western Indian Ocean using two fishing strategies: (1) on floating objects (FOB) and (2) free swimming schools (FSC) using tuna catch and effort data spanning 1992-2019. We show that FOB fishing evolved dramatically through time with an estimated change of 3.6%yr -1 (8.0%yr -1 2007-2019), in contrast to 2.1%yr -1 for FSC. While the efficiency level in combining and using inputs has barely changed for FOB fishing, it means that all the growth in productivity comes from technical change for this strategy. The dynamics is different for the FSC with a mixture of innovation and higher efficiency. Immediate plans to improve input-based management in this region are needed to prevent further risks of overfishing to yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tunas., (© 2023. Springer Nature Limited.)

Published
2023
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42. Diving into the vertical dimension of elasmobranch movement ecology.

Author

Andrzejaczek S, Lucas TCD, Goodman MC, Hussey NE, Armstrong AJ, Carlisle A, Coffey DM, Gleiss AC, Huveneers C, Jacoby DMP, Meekan MG, Mourier J, Peel LR, Abrantes K, Afonso AS, Ajemian MJ, Anderson BN, Anderson SD, Araujo G, Armstrong AO, Bach P, Barnett A, Bennett MB, Bezerra NA, Bonfil R, Boustany AM, Bowlby HD, Branco I, Braun CD, Brooks EJ, Brown J, Burke PJ, Butcher P, Castleton M, Chapple TK, Chateau O, Clarke M, Coelho R, Cortes E, Couturier LIE, Cowley PD, Croll DA, Cuevas JM, Curtis TH, Dagorn L, Dale JJ, Daly R, Dewar H, Doherty PD, Domingo A, Dove ADM, Drew M, Dudgeon CL, Duffy CAJ, Elliott RG, Ellis JR, Erdmann MV, Farrugia TJ, Ferreira LC, Ferretti F, Filmalter JD, Finucci B, Fischer C, Fitzpatrick R, Forget F, Forsberg K, Francis MP, Franks BR, Gallagher AJ, Galvan-Magana F, García ML, Gaston TF, Gillanders BM, Gollock MJ, Green JR, Green S, Griffiths CA, Hammerschlag N, Hasan A, Hawkes LA, Hazin F, Heard M, Hearn A, Hedges KJ, Henderson SM, Holdsworth J, Holland KN, Howey LA, Hueter RE, Humphries NE, Hutchinson M, Jaine FRA, Jorgensen SJ, Kanive PE, Labaja J, Lana FO, Lassauce H, Lipscombe RS, Llewellyn F, Macena BCL, Mambrasar R, McAllister JD, McCully Phillips SR, McGregor F, McMillan MN, McNaughton LM, Mendonça SA, Meyer CG, Meyers M, Mohan JA, Montgomery JC, Mucientes G, Musyl MK, Nasby-Lucas N, Natanson LJ, O'Sullivan JB, Oliveira P, Papastamtiou YP, Patterson TA, Pierce SJ, Queiroz N, Radford CA, Richardson AJ, Richardson AJ, Righton D, Rohner CA, Royer MA, Saunders RA, Schaber M, Schallert RJ, Scholl MC, Seitz AC, Semmens JM, Setyawan E, Shea BD, Shidqi RA, Shillinger GL, Shipley ON, Shivji MS, Sianipar AB, Silva JF, Sims DW, Skomal GB, Sousa LL, Southall EJ, Spaet JLY, Stehfest KM, Stevens G, Stewart JD, Sulikowski JA, Syakurachman I, Thorrold SR, Thums M, Tickler D, Tolloti MT, Townsend KA, Travassos P, Tyminski JP, Vaudo JJ, Veras D, Wantiez L, Weber SB, Wells RJD, Weng KC, Wetherbee BM, Williamson JE, Witt MJ, Wright S, Zilliacus K, Block BA, and Curnick DJ

Abstract

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.

Published
2022
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43. Tuna behaviour at anchored FADs inferred from Local Ecological Knowledge (LEK) of pole-and-line tuna fishers in the Maldives.

Author

Jauharee AR, Capello M, Simier M, Forget F, Adam MS, and Dagorn L

Subjects
Animals, Indian Ocean Islands, Behavior, Animal physiology, Humans, Conservation of Natural Resources methods, Ecosystem, Maldives, Tuna physiology, Fisheries
Abstract

The Maldives tuna fishery landings in 2018 were 148, 000 t and accounted for nearly a quarter of the global pole-and-line tuna catch. This fishery partially relies on a network of 55 anchored fish aggregating devices (AFADs) deployed around the archipelago. About one-third of the total pole-and-line tuna catch is harvested at AFADs. Although the AFAD fishery has existed for 35 years, knowledge on the behaviour of tuna in the AFAD array is still limited, precluding the development of science-based fishery management. In this study, local ecological knowledge (LEK) of fishers was used to improve our understanding of tuna behaviour, through personal interviews of 54 pole-and-line fishers from different parts of the archipelago. Interview results suggest that during the northeast monsoon tuna are more abundant on the eastern side of the Maldives, while during the southwest monsoon they are more abundant on the western side of the Maldives. Most fishers believed that tuna tend to stay at the AFADs for 3 to 6 days and remain within 2 miles from the AFADs when they are associated. Fishers believe that strong currents is the main factor for tuna departure from AFADs, though high sea surface temperatures and stormy conditions were also thought to contribute to departures. Moderate currents are believed to be a favourable condition to form aggregations at the AFADs while other factors such as suitable temperature, prey and attractants enhance this aggregation. Fishers also believe that there are multiple schools segregated according to size and species at AFADs and that catchability is higher at dawn and in the late afternoon when the tuna occur shallower in the water column. This study is an important step towards engaging the Maldivian tuna fishers into a science-based fishery management., Competing Interests: The authors have declared that no competing interests exist.

Published
2021
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44. Recent expansion of marine protected areas matches with home range of grey reef sharks.

Author

Bonnin L, Mouillot D, Boussarie G, Robbins WD, Kiszka JJ, Dagorn L, and Vigliola L

Subjects
Animals, Conservation of Natural Resources, Coral Reefs, Female, Male, Ecosystem, Homing Behavior physiology, Sharks
Abstract

Dramatic declines in reef shark populations have been documented worldwide in response to human activities. Marine Protected Areas (MPAs) offer a useful mechanism to protect these species and their roles in coral reef ecosystems. The effectiveness of MPAs notably relies on compliance together with sufficient size to encompass animal home range. Here, we measured home range of 147 grey reef sharks, Carcharhinus amblyrhynchos, using acoustic telemetry in New Caledonia. The distribution of home range was then compared to local MPA sizes. We report a home range of 12 km 2 of reef for the species with strong differences between adult males (21 km 2 ), adult females (4.4 km 2 ) and juveniles (6.2 km 2 for males, 2.7 km 2 for females). Whereas local historic MPA size seemed adequate to protect reef shark home range in general, these were clearly too small when considering adult males only, which is consistent with the reported failure of MPAs to protect sharks in New Caledonia. Fortunately, the recent implementation of several orders of magnitude larger MPAs in New Caledonia and abroad show that recent Indo-Pacific MPAs are now sufficiently large to protect the home ranges of this species, including males, across its geographical range. However, protection efforts are concentrated in a few regions and cannot provide adequate protection at a global scale., (© 2021. The Author(s).)

Published
2021
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45. Reply to: Caution over the use of ecological big data for conservation.

Author

Queiroz N, Humphries NE, Couto A, Vedor M, da Costa I, Sequeira AMM, Mucientes G, Santos AM, Abascal FJ, Abercrombie DL, Abrantes K, Acuña-Marrero D, Afonso AS, Afonso P, Anders D, Araujo G, Arauz R, Bach P, Barnett A, Bernal D, Berumen ML, Lion SB, Bezerra NPA, Blaison AV, Block BA, Bond ME, Bonfil R, Braun CD, Brooks EJ, Brooks A, Brown J, Byrne ME, Campana SE, Carlisle AB, Chapman DD, Chapple TK, Chisholm J, Clarke CR, Clua EG, Cochran JEM, Crochelet EC, Dagorn L, Daly R, Cortés DD, Doyle TK, Drew M, Duffy CAJ, Erikson T, Espinoza E, Ferreira LC, Ferretti F, Filmalter JD, Fischer GC, Fitzpatrick R, Fontes J, Forget F, Fowler M, Francis MP, Gallagher AJ, Gennari E, Goldsworthy SD, Gollock MJ, Green JR, Gustafson JA, Guttridge TL, Guzman HM, Hammerschlag N, Harman L, Hazin FHV, Heard M, Hearn AR, Holdsworth JC, Holmes BJ, Howey LA, Hoyos M, Hueter RE, Hussey NE, Huveneers C, Irion DT, Jacoby DMP, Jewell OJD, Johnson R, Jordan LKB, Joyce W, Keating Daly CA, Ketchum JT, Klimley AP, Kock AA, Koen P, Ladino F, Lana FO, Lea JSE, Llewellyn F, Lyon WS, MacDonnell A, Macena BCL, Marshall H, McAllister JD, Meÿer MA, Morris JJ, Nelson ER, Papastamatiou YP, Peñaherrera-Palma C, Pierce SJ, Poisson F, Quintero LM, Richardson AJ, Rogers PJ, Rohner CA, Rowat DRL, Samoilys M, Semmens JM, Sheaves M, Shillinger G, Shivji M, Singh S, Skomal GB, Smale MJ, Snyders LB, Soler G, Soria M, Stehfest KM, Thorrold SR, Tolotti MT, Towner A, Travassos P, Tyminski JP, Vandeperre F, Vaudo JJ, Watanabe YY, Weber SB, Wetherbee BM, White TD, Williams S, Zárate PM, Harcourt R, Hays GC, Meekan MG, Thums M, Irigoien X, Eguiluz VM, Duarte CM, Sousa LL, Simpson SJ, Southall EJ, and Sims DW

Subjects
Conservation of Natural Resources, Big Data, Ecology
Published
2021
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46. Reply to: Shark mortality cannot be assessed by fishery overlap alone.

Author

Queiroz N, Humphries NE, Couto A, Vedor M, da Costa I, Sequeira AMM, Mucientes G, Santos AM, Abascal FJ, Abercrombie DL, Abrantes K, Acuña-Marrero D, Afonso AS, Afonso P, Anders D, Araujo G, Arauz R, Bach P, Barnett A, Bernal D, Berumen ML, Lion SB, Bezerra NPA, Blaison AV, Block BA, Bond ME, Bonfil R, Bradford RW, Braun CD, Brooks EJ, Brooks A, Brown J, Bruce BD, Byrne ME, Campana SE, Carlisle AB, Chapman DD, Chapple TK, Chisholm J, Clarke CR, Clua EG, Cochran JEM, Crochelet EC, Dagorn L, Daly R, Cortés DD, Doyle TK, Drew M, Duffy CAJ, Erikson T, Espinoza E, Ferreira LC, Ferretti F, Filmalter JD, Fischer GC, Fitzpatrick R, Fontes J, Forget F, Fowler M, Francis MP, Gallagher AJ, Gennari E, Goldsworthy SD, Gollock MJ, Green JR, Gustafson JA, Guttridge TL, Guzman HM, Hammerschlag N, Harman L, Hazin FHV, Heard M, Hearn AR, Holdsworth JC, Holmes BJ, Howey LA, Hoyos M, Hueter RE, Hussey NE, Huveneers C, Irion DT, Jacoby DMP, Jewell OJD, Johnson R, Jordan LKB, Joyce W, Keating Daly CA, Ketchum JT, Klimley AP, Kock AA, Koen P, Ladino F, Lana FO, Lea JSE, Llewellyn F, Lyon WS, MacDonnell A, Macena BCL, Marshall H, McAllister JD, Meÿer MA, Morris JJ, Nelson ER, Papastamatiou YP, Peñaherrera-Palma C, Pierce SJ, Poisson F, Quintero LM, Richardson AJ, Rogers PJ, Rohner CA, Rowat DRL, Samoilys M, Semmens JM, Sheaves M, Shillinger G, Shivji M, Singh S, Skomal GB, Smale MJ, Snyders LB, Soler G, Soria M, Stehfest KM, Thorrold SR, Tolotti MT, Towner A, Travassos P, Tyminski JP, Vandeperre F, Vaudo JJ, Watanabe YY, Weber SB, Wetherbee BM, White TD, Williams S, Zárate PM, Harcourt R, Hays GC, Meekan MG, Thums M, Irigoien X, Eguiluz VM, Duarte CM, Sousa LL, Simpson SJ, Southall EJ, and Sims DW

Subjects
Animals, Conservation of Natural Resources, Seafood, Fisheries, Sharks
Published
2021
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47. Does the Composition of the Gut Bacteriome Change during the Growth of Tuna?

Author

Gadoin E, Durand L, Guillou A, Crochemore S, Bouvier T, Roque E, Dagorn L, Auguet JC, Adingra A, Desnues C, and Bettarel Y

Abstract

In recent years, a growing number of studies sought to examine the composition and the determinants of the gut microflora in marine animals, including fish. For tropical tuna, which are among the most consumed fish worldwide, there is scarce information on their enteric bacterial communities and how they evolve during fish growth. In this study, we used metabarcoding of the 16S rDNA gene to (1) describe the diversity and composition of the gut bacteriome in the three most fished tuna species (skipjack, yellowfin and bigeye), and (2) to examine its intra-specific variability from juveniles to larger adults. Although there was a remarkable convergence of taxonomic richness and bacterial composition between yellowfin and bigeyes tuna, the gut bacteriome of skipjack tuna was distinct from the other two species. Throughout fish growth, the enteric bacteriome of yellowfin and bigeyes also showed significant modifications, while that of skipjack tuna remained relatively homogeneous. Finally, our results suggest that the gut bacteriome of marine fish may not always be subject to structural modifications during their growth, especially in species that maintain a steady feeding behavior during their lifetime.

Published
2021
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48. Effects of habitat modifications on the movement behavior of animals: the case study of Fish Aggregating Devices (FADs) and tropical tunas.

Author

Pérez G, Dagorn L, Deneubourg JL, Forget F, Filmalter JD, Holland K, Itano D, Adam S, Jauharee R, Beeharry SP, and Capello M

Abstract

Background: Aggregation sites represent important sources of environmental heterogeneity and can modify the movement behavior of animals. When these sites are artificially established through anthropogenic actions, the consequent alterations to animal movements may impact their ecology with potential implications for their fitness. Floating objects represent important sources of habitat heterogeneity for tropical tunas, beneath which these species naturally aggregate in large numbers. Man-made floating objects, called Fish Aggregating Devices (FAD), are used by fishers on a massive scale to facilitate fishing operations. In addition to the direct impacts that fishing with FADs has on tuna populations, assessing the effects of increasing the numbers of FADs on the ecology of tuna is key for generating sound management and conservation measures., Methods: This study investigates the effects of increasing numbers of FADs (aggregation sites) on the movements of tunas, through the comparison of electronic tagging data recorded from 146 individuals tunas (yellowfin tuna, Thunnus albacares, and skipjack tuna, Katsuwonus pelamis) tagged in three instrumented anchored FAD arrays (Mauritius, Oahu-Hawaii and Maldives), that differed according to their distances among neighboring FADs. The effect of increasing inter-FAD distances is studied considering a set of indices (residence times at FADs and absence (travel) times between two visits at FADs) and their trends., Results: When inter-FAD distances decrease, tuna visit more FADs (higher connectivity between FADs), spend less time travelling between FADs and more time associated with them. The trends observed for the absence (travel) times appear to be compatible with a random-search component in the movement behaviour of tunas. Conversely, FAD residence times showed opposite trends, which could be a result of social behavior and/or prey availability., Conclusion: Our results provide the first evidence of changes in tuna associative behavior for increasing FAD densities. More generally, they highlight the need for comparing animal movements in heterogeneous habitats in order to improve understanding of the impacts of anthropogenic habitat modifications on the ecology of wild animals.

Published
2020
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49. Global spatial risk assessment of sharks under the footprint of fisheries.

Author

Queiroz N, Humphries NE, Couto A, Vedor M, da Costa I, Sequeira AMM, Mucientes G, Santos AM, Abascal FJ, Abercrombie DL, Abrantes K, Acuña-Marrero D, Afonso AS, Afonso P, Anders D, Araujo G, Arauz R, Bach P, Barnett A, Bernal D, Berumen ML, Bessudo Lion S, Bezerra NPA, Blaison AV, Block BA, Bond ME, Bonfil R, Bradford RW, Braun CD, Brooks EJ, Brooks A, Brown J, Bruce BD, Byrne ME, Campana SE, Carlisle AB, Chapman DD, Chapple TK, Chisholm J, Clarke CR, Clua EG, Cochran JEM, Crochelet EC, Dagorn L, Daly R, Cortés DD, Doyle TK, Drew M, Duffy CAJ, Erikson T, Espinoza E, Ferreira LC, Ferretti F, Filmalter JD, Fischer GC, Fitzpatrick R, Fontes J, Forget F, Fowler M, Francis MP, Gallagher AJ, Gennari E, Goldsworthy SD, Gollock MJ, Green JR, Gustafson JA, Guttridge TL, Guzman HM, Hammerschlag N, Harman L, Hazin FHV, Heard M, Hearn AR, Holdsworth JC, Holmes BJ, Howey LA, Hoyos M, Hueter RE, Hussey NE, Huveneers C, Irion DT, Jacoby DMP, Jewell OJD, Johnson R, Jordan LKB, Jorgensen SJ, Joyce W, Keating Daly CA, Ketchum JT, Klimley AP, Kock AA, Koen P, Ladino F, Lana FO, Lea JSE, Llewellyn F, Lyon WS, MacDonnell A, Macena BCL, Marshall H, McAllister JD, McAuley R, Meÿer MA, Morris JJ, Nelson ER, Papastamatiou YP, Patterson TA, Peñaherrera-Palma C, Pepperell JG, Pierce SJ, Poisson F, Quintero LM, Richardson AJ, Rogers PJ, Rohner CA, Rowat DRL, Samoilys M, Semmens JM, Sheaves M, Shillinger G, Shivji M, Singh S, Skomal GB, Smale MJ, Snyders LB, Soler G, Soria M, Stehfest KM, Stevens JD, Thorrold SR, Tolotti MT, Towner A, Travassos P, Tyminski JP, Vandeperre F, Vaudo JJ, Watanabe YY, Weber SB, Wetherbee BM, White TD, Williams S, Zárate PM, Harcourt R, Hays GC, Meekan MG, Thums M, Irigoien X, Eguiluz VM, Duarte CM, Sousa LL, Simpson SJ, Southall EJ, and Sims DW

Subjects
Animals, Population Density, Risk Assessment, Sharks classification, Ships, Time Factors, Animal Migration, Fisheries statistics & numerical data, Geographic Mapping, Oceans and Seas, Sharks physiology, Spatio-Temporal Analysis
Abstract

Effective ocean management and the conservation of highly migratory species depend on resolving the overlap between animal movements and distributions, and fishing effort. However, this information is lacking at a global scale. Here we show, using a big-data approach that combines satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space-use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively), and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of fishing effort in marine areas beyond national jurisdictions (the high seas). Our results demonstrate an urgent need for conservation and management measures at high-seas hotspots of shark space use, and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real-time, dynamic management.

Published
2019
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50. Vulnerability of the Oceanic Whitetip Shark to Pelagic Longline Fisheries.

Author

Tolotti MT, Bach P, Hazin F, Travassos P, and Dagorn L

Subjects
Animals, Geography, Population Dynamics, Conservation of Natural Resources, Ecosystem, Fisheries, Sharks physiology
Abstract

A combination of fisheries dependent and independent data was used to assess the vulnerability of the oceanic whitetip shark to pelagic longline fisheries. The Brazilian tuna longline fleet, operating in the equatorial and southwestern Atlantic, is used as a case study. Fisheries dependent data include information from logbooks (from 1999 to 2011) and on-board observers (2004 to 2010), totaling 65,277 pelagic longline sets. Fisheries independent data were obtained from 8 oceanic whitetip sharks tagged with pop-up satellite archival tags in the area where longline fleet operated. Deployment periods varied from 60 to 178 days between 2010 and 2012. Tagging and pop-up sites were relatively close to each other, although individuals tended to travel long distances before returning to the tagging area. Some degree of site fidelity was observed. High utilization hotspots of tagged sharks fell inside the area under strongest fishing pressure. Despite the small sample size, a positive correlation between tag recorded information and catch data was detected. All sharks exhibited a strong preference for the warm and shallow waters of the mixed layer, spending on average more than 70% of the time above the thermocline and 95% above 120 m. Results indicate that the removal of shallow hooks on longline gear might be an efficient mitigation measure to reduce the bycatch of this pelagic shark species. The work also highlights the potential of tagging experiments to provide essential information for the development of spatio-temporal management measures.

Published
2015
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