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1. Identifying priority sites for whale shark ship collision management globally

Author

Womersley, Freya C., Rohner, Christoph A., Abrantes, Kátya, Afonso, Pedro, Arunrugstichai, Shin, Bach, Steffen S., Bar, Shir, Barash, Adi, Barnes, Peter, Barnett, Adam, Boldrocchi, Ginevra, Buffat, Noemie, Canon, Tom, Perez, Clara Canovas, Chuangcharoendee, Metavee, Cochran, Jesse E.M., de la Parra, Rafael, Diamant, Stella, Driggers, William, Dudgeon, Christine L., Erdmann, Mark V., Fitzpatrick, Richard, Flam, Anna, Fontes, Jorge, Francis, Gemma, Galvan, Beatriz Eugenia, Graham, Rachel T., Green, Sofia M., Green, Jonathan R., Grosmark, Ya'ara, Guzman, Hector M., Hardenstine, Royale S., Harvey, Maria, Harvey-Carroll, Jessica, Hasan, Abdi Wunanto, Hearn, Alex R., Hendon, Jill M., Putra, Mochamad Iqbal Herwata, Himawan, Mahardika Rizqi, Hoffmayer, Eric, Holmberg, Jason, Hsu, Hua Hsun, Jaidah, Mohammed Y., Jansen, Ashlee, Judd, Christy, Kuguru, Baraka, Lester, Emily, Macena, Bruno C.L., Magson, Kirsty, Maguiño, Rossana, Manjaji-Matsumoto, Mabel, Marcoux, Stacia D., Marcoux, Travis, McKinney, Jennifer, Meekan, Mark, Mendoza, Alejandra, Moazzam, Muhammad, Monacella, Emily, Norman, Brad, Perry, Cameron, Pierce, Simon, Prebble, Clare, Macías, Dení Ramírez, Raudino, Holly, Reynolds, Samantha, Robinson, David, Rowat, David, Santos, Mudjekeewis D., Schmidt, Jennifer, Scott, Chad, See, Sian Tian, Sianipar, Abraham, Speed, Conrad W., Syakurachman, Ismail, Tyne, Julian A., Waples, Kelly, Winn, Chloe, Yuneni, Ranny R., Zareer, Irthisham, and Araujo, Gonzalo

Published
2024
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2. Global collision-risk hotspots of marine traffic and the world’s largest fish, the whale shark

Author

Womersley, Freya C., Humphries, Nicolas E., Queiroz, Nuno, Vedor, Marisa, da Costa, Ivo, Furtado, Miguel, Tyminski, John P., Abrantes, Katya, Araujo, Gonzalo, Bach, Steffen S., Barnett, Adam, Berumen, Michael L., Lion, Sandrao Bessudo, Braun, Camrin D., Clingham, Elizabeth, Cochran, Jesse E. M., de la Parra, Rafael, Diamant, Stella, Dove, Alistair D. M., Dudgeon, Christine L., Erdmann, Mark V., Espinoza, Eduardo, Fitzpatrick, Richard, Cano, Jaime González, Green, Jonathan R., Guzman, Hector M., Hardenstine, Royale, Hasan, Abdi, Hazina, Fábio H. V., Hearn, Alex R., Hueter, Robert E., Jaidah, Mohammed Y., Labaja, Jessica, Ladino, Felipe, Macena, Bruno C. L., Morris, John J., Norman, Bradley M., Peñaherrera-Palma, Cesar, Pierce, Simon J., Quintero, Lina M., Ramírez-Macías, Dení, Reynolds, Samantha D., Richardson, Anthony J., Robinson, David P., Rohner, Christoph A., Rowat, David R. L., Sheaves, Marcus, Shivjio, Mahmood S., Sianipar, Abraham B., Skomal, Gregory B., Soler, German, Syakurachman, Ismail, Thorrold, Simon R., Webb, D. Harry, Wetherbee, Bradley M., White, Timothy D., Clavelle, Tyler, Kroodsma, David A., Thums, Michele, Ferreira, Luciana C., Meekan, Mark G., Arrowsmith, Lucy M., Lester, Emily K., Meyers, Megan M., Peel, Lauren R., Sequeira, Ana M. M., Eguíluz, Victor M., Duarte, Carlos M., and Sims, David W.

Published
2022

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

Author

Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, da Costa, Ivo, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, Acuña-Marrero, David, Afonso, André S., Afonso, Pedro, Anders, Darrell, Araujo, Gonzalo, Arauz, Randall, Bach, Pascal, Barnett, Adam, Bernal, Diego, Berumen, Michael L., Lion, Sandra Bessudo, Bezerra, Natalia P. A., Blaison, Antonin V., Block, Barbara A., Bond, Mark E., Bonfil, Ramon, Bradford, Russell W., Braun, Camrin D., Brooks, Edward J., Brooks, Annabelle, Brown, Judith, Bruce, Barry D., Byrne, Michael E., Campana, Steven E., Carlisle, Aaron B., Chapman, Demian D., Chapple, Taylor K., Chisholm, John, Clarke, Christopher R., Clua, Eric G., Cochran, Jesse E. M., Crochelet, Estelle C., Dagorn, Laurent, Daly, Ryan, Cortés, Daniel Devia, Doyle, Thomas K., Drew, Michael, Duffy, Clinton A. J., Erikson, Thor, Espinoza, Eduardo, Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Fischer, G. Chris, Fitzpatrick, Richard, Fontes, Jorge, Forget, Fabien, Fowler, Mark, Francis, Malcolm P., Gallagher, Austin J., Gennari, Enrico, Goldsworthy, Simon D., Gollock, Matthew J., Green, Jonathan R., Gustafson, Johan A., Guttridge, Tristan L., Guzman, Hector M., Hammerschlag, Neil, Harman, Luke, Hazin, Fábio H. V., Heard, Matthew, Hearn, Alex R., Holdsworth, John C., Holmes, Bonnie J., Howey, Lucy A., Hoyos, Mauricio, Hueter, Robert E., Hussey, Nigel E., Huveneers, Charlie, Irion, Dylan T., Jacoby, David M. P., Jewell, Oliver J. D., Johnson, Ryan, Jordan, Lance K. B., Joyce, Warren, Keating Daly, Clare A., Ketchum, James T., Klimley, A. Peter, Kock, Alison A., Koen, Pieter, Ladino, Felipe, Lana, Fernanda O., Lea, James S. E., Llewellyn, Fiona, Lyon, Warrick S., MacDonnell, Anna, Macena, Bruno C. L., Marshall, Heather, McAllister, Jaime D., Meÿer, Michael A., Morris, John J., Nelson, Emily R., Papastamatiou, Yannis P., Peñaherrera-Palma, Cesar, Pierce, Simon J., Poisson, Francois, Quintero, Lina Maria, Richardson, Andrew J., Rogers, Paul J., Rohner, Christoph A., Rowat, David R. L., Samoilys, Melita, Semmens, Jayson M., Sheaves, Marcus, Shillinger, George, Shivji, Mahmood, Singh, Sarika, Skomal, Gregory B., Smale, Malcolm J., Snyders, Laurenne B., Soler, German, Soria, Marc, Stehfest, Kilian M., Thorrold, Simon R., Tolotti, Mariana T., Towner, Alison, Travassos, Paulo, Tyminski, John P., Vandeperre, Frederic, Vaudo, Jeremy J., Watanabe, Yuuki Y., Weber, Sam B., Wetherbee, Bradley M., White, Timothy D., Williams, Sean, Zárate, Patricia M., Harcourt, Robert, Hays, Graeme C., Meekan, Mark G., Thums, Michele, Irigoien, Xabier, Eguiluz, Victor M., Duarte, Carlos M., Sousa, Lara L., Simpson, Samantha J., Southall, Emily J., and Sims, David W.

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

Author

Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, da Costa, Ivo, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, Acuña-Marrero, David, Afonso, André S., Afonso, Pedro, Anders, Darrell, Araujo, Gonzalo, Arauz, Randall, Bach, Pascal, Barnett, Adam, Bernal, Diego, Berumen, Michael L., Lion, Sandra Bessudo, Bezerra, Natalia P. A., Blaison, Antonin V., Block, Barbara A., Bond, Mark E., Bonfil, Ramon, Braun, Camrin D., Brooks, Edward J., Brooks, Annabelle, Brown, Judith, Byrne, Michael E., Campana, Steven E., Carlisle, Aaron B., Chapman, Demian D., Chapple, Taylor K., Chisholm, John, Clarke, Christopher R., Clua, Eric G., Cochran, Jesse E. M., Crochelet, Estelle C., Dagorn, Laurent, Daly, Ryan, Cortés, Daniel Devia, Doyle, Thomas K., Drew, Michael, Duffy, Clinton A. J., Erikson, Thor, Espinoza, Eduardo, Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Fischer, G. Chris, Fitzpatrick, Richard, Fontes, Jorge, Forget, Fabien, Fowler, Mark, Francis, Malcolm P., Gallagher, Austin J., Gennari, Enrico, Goldsworthy, Simon D., Gollock, Matthew J., Green, Jonathan R., Gustafson, Johan A., Guttridge, Tristan L., Guzman, Hector M., Hammerschlag, Neil, Harman, Luke, Hazin, Fábio H. V., Heard, Matthew, Hearn, Alex R., Holdsworth, John C., Holmes, Bonnie J., Howey, Lucy A., Hoyos, Mauricio, Hueter, Robert E., Hussey, Nigel E., Huveneers, Charlie, Irion, Dylan T., Jacoby, David M. P., Jewell, Oliver J. D., Johnson, Ryan, Jordan, Lance K. B., Joyce, Warren, Keating Daly, Clare A., Ketchum, James T., Klimley, A. Peter, Kock, Alison A., Koen, Pieter, Ladino, Felipe, Lana, Fernanda O., Lea, James S. E., Llewellyn, Fiona, Lyon, Warrick S., MacDonnell, Anna, Macena, Bruno C. L., Marshall, Heather, McAllister, Jaime D., Meÿer, Michael A., Morris, John J., Nelson, Emily R., Papastamatiou, Yannis P., Peñaherrera-Palma, Cesar, Pierce, Simon J., Poisson, Francois, Quintero, Lina Maria, Richardson, Andrew J., Rogers, Paul J., Rohner, Christoph A., Rowat, David R. L., Samoilys, Melita, Semmens, Jayson M., Sheaves, Marcus, Shillinger, George, Shivji, Mahmood, Singh, Sarika, Skomal, Gregory B., Smale, Malcolm J., Snyders, Laurenne B., Soler, German, Soria, Marc, Stehfest, Kilian M., Thorrold, Simon R., Tolotti, Mariana T., Towner, Alison, Travassos, Paulo, Tyminski, John P., Vandeperre, Frederic, Vaudo, Jeremy J., Watanabe, Yuuki Y., Weber, Sam B., Wetherbee, Bradley M., White, Timothy D., Williams, Sean, Zárate, Patricia M., Harcourt, Robert, Hays, Graeme C., Meekan, Mark G., Thums, Michele, Irigoien, Xabier, Eguiluz, Victor M., Duarte, Carlos M., Sousa, Lara L., Simpson, Samantha J., Southall, Emily J., and Sims, David W.

Published
2021
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9. Global spatial risk assessment of sharks under the footprint of fisheries

Author

Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, da Costa, Ivo, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, Acuña-Marrero, David, Afonso, André S., Afonso, Pedro, Anders, Darrell, Araujo, Gonzalo, Arauz, Randall, Bach, Pascal, Barnett, Adam, Bernal, Diego, Berumen, Michael L., Bessudo Lion, Sandra, Bezerra, Natalia P. A., Blaison, Antonin V., Block, Barbara A., Bond, Mark E., Bonfil, Ramón, Bradford, Russell W., Braun, Camrin D., Brooks, Edward J., Brooks, Annabelle, Brown, Judith, Bruce, Barry D., Byrne, Michael E., Campana, Steven E., Carlisle, Aaron B., Chapman, Demian D., Chapple, Taylor K., Chisholm, John, Clarke, Christopher R., Clua, Eric G., Cochran, Jesse E. M., Crochelet, Estelle C., Dagorn, Laurent, Daly, Ryan, Cortés, Daniel Devia, Doyle, Thomas K., Drew, Michael, Duffy, Clinton A. J., Erikson, Thor, Espinoza, Eduardo, Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Fischer, G. Chris, Fitzpatrick, Richard, Fontes, Jorge, Forget, Fabien, Fowler, Mark, Francis, Malcolm P., Gallagher, Austin J., Gennari, Enrico, Goldsworthy, Simon D., Gollock, Matthew J., Green, Jonathan R., Gustafson, Johan A., Guttridge, Tristan L., Guzman, Hector M., Hammerschlag, Neil, Harman, Luke, Hazin, Fábio H. V., Heard, Matthew, Hearn, Alex R., Holdsworth, John C., Holmes, Bonnie J., Howey, Lucy A., Hoyos, Mauricio, Hueter, Robert E., Hussey, Nigel E., Huveneers, Charlie, Irion, Dylan T., Jacoby, David M. P., Jewell, Oliver J. D., Johnson, Ryan, Jordan, Lance K. B., Jorgensen, Salvador J., Joyce, Warren, Keating Daly, Clare A., Ketchum, James T., Klimley, A. Peter, Kock, Alison A., Koen, Pieter, Ladino, Felipe, Lana, Fernanda O., Lea, James S. E., Llewellyn, Fiona, Lyon, Warrick S., MacDonnell, Anna, Macena, Bruno C. L., Marshall, Heather, McAllister, Jaime D., McAuley, Rory, Meÿer, Michael A., Morris, John J., Nelson, Emily R., Papastamatiou, Yannis P., Patterson, Toby A., Peñaherrera-Palma, Cesar, Pepperell, Julian G., Pierce, Simon J., Poisson, Francois, Quintero, Lina Maria, Richardson, Andrew J., Rogers, Paul J., Rohner, Christoph A., Rowat, David R. L., Samoilys, Melita, Semmens, Jayson M., Sheaves, Marcus, Shillinger, George, Shivji, Mahmood, Singh, Sarika, Skomal, Gregory B., Smale, Malcolm J., Snyders, Laurenne B., Soler, German, Soria, Marc, Stehfest, Kilian M., Stevens, John D., Thorrold, Simon R., Tolotti, Mariana T., Towner, Alison, Travassos, Paulo, Tyminski, John P., Vandeperre, Frederic, Vaudo, Jeremy J., Watanabe, Yuuki Y., Weber, Sam B., Wetherbee, Bradley M., White, Timothy D., Williams, Sean, Zárate, Patricia M., Harcourt, Robert, Hays, Graeme C., Meekan, Mark G., Thums, Michele, Irigoien, Xabier, Eguiluz, Victor M., Duarte, Carlos M., Sousa, Lara L., Simpson, Samantha J., Southall, Emily J., and Sims, David W.

Published
2019
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20. GlobalSharkMovement / GlobalCollisionRisk

Author

Womersley, Freya C., Humphries, Nicolas E., Queiroz, Nuno, Vedor, Marisa, Costa, Ivo da, Furtado, Miguel, Tyminski, John P., Abrantes, Katya, Araujo, Gonzalo, Bach, Steffen S., Barnett, Adam, Berumen, Michael L., Bessudo Lion, Sandra, Braun, Camrin D., Clingham, Elizabeth, Cochran, Jesse E. M., Parra, Rafael de la, Diamant, Stella, Dove, Alistair D. M., Dudgeon, Christine L., Erdmann, Mark V., Espinoza, Eduardo, Fitzpatrick, Richard, González Cano , Jaime, Green, Jonathan R., Guzman, Hector M., Hardenstine, Royale, Hasan, Abdi, Hazin, Fábio H. V., Hearn, Alex R., Hueter, Robert E., Jaidah, Mohammed Y., Labaja, Jessica, Ladino, Felipe, Macena, Bruno C. L., Morris, John J., Norman, Bradley M., Peñaherrera-Palma, Cesar, Pierce, Simon J., Quintero, Lina M., Ramírez-Macías, Dení, Reynolds, Samantha D., Richardson, Anthony J., Robinson, David P., Rohner, Christoph A., Rowat, David R. L., Sheaves, Marcus, Shivji, Mahmood S., Sianipar, Abraham B., Skomal, Gregory B., Soler, German, Syakurachman, Ismail, Thorrold, Simon R., Webb, D. Harry, Wetherbee, Bradley M., White, Timothy D., Clavelle, Tyler, Kroodsma, David A., Thums, Michele, Ferreira, Luciana C., Meekan, Mark G., Arrowsmith, Lucy M., Lester, Emily K., Meyers, Megan M., Peel, Lauren R., Sequeira, Ana M. M., Eguíluz, Víctor M., Duarte, Carlos M., Sims, David W., Womersley, Freya C., Humphries, Nicolas E., Queiroz, Nuno, Vedor, Marisa, Costa, Ivo da, Furtado, Miguel, Tyminski, John P., Abrantes, Katya, Araujo, Gonzalo, Bach, Steffen S., Barnett, Adam, Berumen, Michael L., Bessudo Lion, Sandra, Braun, Camrin D., Clingham, Elizabeth, Cochran, Jesse E. M., Parra, Rafael de la, Diamant, Stella, Dove, Alistair D. M., Dudgeon, Christine L., Erdmann, Mark V., Espinoza, Eduardo, Fitzpatrick, Richard, González Cano , Jaime, Green, Jonathan R., Guzman, Hector M., Hardenstine, Royale, Hasan, Abdi, Hazin, Fábio H. V., Hearn, Alex R., Hueter, Robert E., Jaidah, Mohammed Y., Labaja, Jessica, Ladino, Felipe, Macena, Bruno C. L., Morris, John J., Norman, Bradley M., Peñaherrera-Palma, Cesar, Pierce, Simon J., Quintero, Lina M., Ramírez-Macías, Dení, Reynolds, Samantha D., Richardson, Anthony J., Robinson, David P., Rohner, Christoph A., Rowat, David R. L., Sheaves, Marcus, Shivji, Mahmood S., Sianipar, Abraham B., Skomal, Gregory B., Soler, German, Syakurachman, Ismail, Thorrold, Simon R., Webb, D. Harry, Wetherbee, Bradley M., White, Timothy D., Clavelle, Tyler, Kroodsma, David A., Thums, Michele, Ferreira, Luciana C., Meekan, Mark G., Arrowsmith, Lucy M., Lester, Emily K., Meyers, Megan M., Peel, Lauren R., Sequeira, Ana M. M., Eguíluz, Víctor M., Duarte, Carlos M., and Sims, David W.

Abstract

Repository containing derived data for the manuscript 'Global collision-risk hotspots of marine traffic and the world's largest fish, the whale shark'.

Published
2022

21. Global collision-risk hotspots of marine traffic and the world’s largest fish, the whale shark

Author

Natural Environment Research Council (UK), European Research Council, Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Womersley, Freya C., Humphries, Nicolas E., Queiroz, Nuno, Vedor, Marisa, Costa, Ivo da, Furtado, Miguel, Tyminski, John P., Abrantes, Katya, Araujo, Gonzalo, Bach, Steffen S., Barnett, Adam, Berumen, Michael L., Bessudo Lion, Sandra, Braun, Camrin D., Clingham, Elizabeth, Cochran, Jesse E. M., Parra, Rafael de la, Diamant, Stella, Dove, Alistair D. M., Dudgeon, Christine L., Erdmann, Mark V., Espinoza, Eduardo, Fitzpatrick, Richard, González Cano , Jaime, Green, Jonathan R., Guzman, Hector M., Hardenstine, Royale, Hasan, Abdi, Hazin, Fábio H. V., Hearn, Alex R., Hueter, Robert E., Jaidah, Mohammed Y., Labaja, Jessica, Ladino, Felipe, Macena, Bruno C. L., Morris, John J., Norman, Bradley M., Peñaherrera-Palma, Cesar, Pierce, Simon J., Quintero, Lina M., Ramírez-Macías, Dení, Reynolds, Samantha D., Richardson, Anthony J., Robinson, David P., Rohner, Christoph A., Rowat, David R. L., Sheaves, Marcus, Shivji, Mahmood S., Sianipar, Abraham B., Skomal, Gregory B., Soler, German, Syakurachman, Ismail, Thorrold, Simon R., Webb, D. Harry, Wetherbee, Bradley M., White, Timothy D., Clavelle, Tyler, Kroodsma, David A., Thums, Michele, Ferreira, Luciana C., Meekan, Mark G., Arrowsmith, Lucy M., Lester, Emily K., Meyers, Megan M., Peel, Lauren R., Sequeira, Ana M. M., Eguíluz, Víctor M., Duarte, Carlos M., Sims, David W., Natural Environment Research Council (UK), European Research Council, Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Womersley, Freya C., Humphries, Nicolas E., Queiroz, Nuno, Vedor, Marisa, Costa, Ivo da, Furtado, Miguel, Tyminski, John P., Abrantes, Katya, Araujo, Gonzalo, Bach, Steffen S., Barnett, Adam, Berumen, Michael L., Bessudo Lion, Sandra, Braun, Camrin D., Clingham, Elizabeth, Cochran, Jesse E. M., Parra, Rafael de la, Diamant, Stella, Dove, Alistair D. M., Dudgeon, Christine L., Erdmann, Mark V., Espinoza, Eduardo, Fitzpatrick, Richard, González Cano , Jaime, Green, Jonathan R., Guzman, Hector M., Hardenstine, Royale, Hasan, Abdi, Hazin, Fábio H. V., Hearn, Alex R., Hueter, Robert E., Jaidah, Mohammed Y., Labaja, Jessica, Ladino, Felipe, Macena, Bruno C. L., Morris, John J., Norman, Bradley M., Peñaherrera-Palma, Cesar, Pierce, Simon J., Quintero, Lina M., Ramírez-Macías, Dení, Reynolds, Samantha D., Richardson, Anthony J., Robinson, David P., Rohner, Christoph A., Rowat, David R. L., Sheaves, Marcus, Shivji, Mahmood S., Sianipar, Abraham B., Skomal, Gregory B., Soler, German, Syakurachman, Ismail, Thorrold, Simon R., Webb, D. Harry, Wetherbee, Bradley M., White, Timothy D., Clavelle, Tyler, Kroodsma, David A., Thums, Michele, Ferreira, Luciana C., Meekan, Mark G., Arrowsmith, Lucy M., Lester, Emily K., Meyers, Megan M., Peel, Lauren R., Sequeira, Ana M. M., Eguíluz, Víctor M., Duarte, Carlos M., and Sims, David W.

Abstract

Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks’ horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (>300 gross tons) traffic. Collision-risk estimates correlated with reported whale shark mortality from ship strikes, indicating higher mortality in areas with greatest overlap. Hotspots of potential collision risk were evident in all major oceans, predominantly from overlap with cargo and tanker vessels, and were concentrated in gulf regions, where dense traffic co-occurred with seasonal shark movements. Nearly a third of whale shark hotspots overlapped with the highest collision-risk areas, with the last known locations of tracked sharks coinciding with busier shipping routes more often than expected. Depth-recording tags provided evidence for sinking, likely dead, whale sharks, suggesting substantial “cryptic” lethal ship strikes are possible, which could explain why whale shark population declines continue despite international protection and low fishing-induced mortality. Mitigation measures to reduce ship-strike risk should be considered to conserve this species and other ocean giants that are likely experiencing similar impacts from growing global vessel traffic., [Significance] Global vessel traffic is increasing alongside world economic growth. The potential for rising lethal ship strikes on endangered species of marine megafauna, such as the plankton-feeding whale shark, remains poorly understood since areas of highest overlap are seldom determined across an entire species range. Here we show how satellite tracking whale sharks and large vessel movements globally provides a means to localize high-overlap areas and to determine how collision risk changes in time. Our results point to potential high levels of undetected or unreported ship strikes, which may explain why whale shark populations continue to decline despite protection and low fishing-induced mortality. Collision mitigations in high-collision-risk areas appear necessary to help conserve this iconic species.

Published
2022

23. Diving into the vertical dimension of elasmobranch movement ecology

Author

Andrzejaczek, Samantha, Lucas, Tim C. D., Goodman, Maurice C., Hussey, Nigel E., Armstrong, Amelia J., Carlisle, Aaron, Gleiss, Adrian C., Huveneers, Charlie, Jacoby, David M. P., Meekan, Mark G., Mourier, Johann, Abrantes, Katya, Afonso, Andre S., Ajemian, Matthew J., Anderson, Brooke N., Anderson, Scot D., Araujo, Gonzalo, Armstrong, Asia O., Bach, Pascal, Barnett, Adam, Bennett, Mike B., Bezerra, Natalia A., Boustany, Andre M., Bowlby, Heather D., Branco, Ilka, Braun, Camrin D., Brooks, Edward J., Burke, Patrick J., Butcher, Paul, Castleton, Michael, Chapple, Taylor K., Clarke, Maurice, Coelho, Rui, Cortes, Enric, Couturier, Lydie I. E., Cowley, Paul D., Croll, Donald A., Cuevas, Juan M., Curtis, Tobey H., Dagorn, Laurent, Dale, Jonathan J., Daly, Ryan, Dewar, Heidi, Doherty, Philip D., Domingo, Andres, Dove, Alistair D. M., Drew, Michael, Dudgeon, Christine L., Duffy, Clinton A. J., Elliott, Riley G., Ellis, Jim R., Erdmann, Mark, Farrugia, Thomas J., Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Finucci, Brittany, Fischer, Chris, Fitzpatrick, Richard, Forget, Fabien, Forsberg, Kerstin, Francis, Malcolm P., Franks, Bryan R., Gallagher, Austin J., Galvan-Magana, Felipe, Garcia, Mirta L., Gaston, Troy F., Gillanders, Bronwyn M., Gollock, Matthew J., Green, Jonathan R., Green, Sofia, Griffiths, Christopher, Hammerschlag, Neil, Hasan, Abdi, Hawkes, Lucy A., Hazin, Fabio, Heard, Matthew, Hearn, Alex, Hedges, Kevin J., Henderson, Suzanne M., Holdsworth, John, Holland, Kim N., Howey, Lucy A., Hueter, Robert E., Humphries, Nicholas E., Hutchinson, Melanie, Jaine, Fabrice R. A., Jorgensen, Salvador J., Kanive, Paul E., Labaja, Jessica, Lana, Fernanda O., Lassauce, Hugo, Lipscombe, Rebecca S., Llewellyn, Fiona, Macena, Bruno C. L., Mambrasar, Ronald, McAllister, Jaime D., Phillips, Sophy R. McCully, McGregor, Frazer, McMillan, Matthew N., McNaughton, Lianne M., Mendonca, Sibele A., Meyer, Carl G., Meyers, Megan, Mohan, John A., Montgomery, John C., Mucientes, Gonzalo, Musyl, Michael K., Nasby-Lucas, Nicole, Natanson, Lisa J., O'Sullivan, John B., Oliveira, Paulo, Papastamtiou, Yannis P., Patterson, Toby A., Pierce, Simon J., Queiroz, Nuno, Radford, Craig A., Richardson, Anthony J., Righton, David, Rohner, Christoph A., Royer, Mark A., Saunders, Ryan A., Schaber, Matthias, Schallert, Robert J., Scholl, Michael C., Seitz, Andrew C., Semmens, Jayson M., Setyawan, Edy, Shea, Brendan D., Shidqi, Rafid A., Shillinger, George L., Shipley, Oliver N., Shivji, Mahmood S., Sianipar, Abraham B., Silva, Joana F., Sims, David W., Skomal, Gregory B., Sousa, Lara L., Southall, Emily J., Spaet, Julia L. Y., Stehfest, Kilian M., Stewart, Joshua D., Sulikowski, James A., Syakurachman, Ismail, Thorrold, Simon R., Thums, Michele, Tickler, David, Tolloti, Mariana T., Townsend, Kathy A., Travassos, Paulo, Tyminski, John P., Vaudo, Jeremy J., Veras, Drausio, Wantiez, Laurent, Weber, Sam B., Wells, R. J. David, Weng, Kevin C., Wetherbee, Bradley M., Williamson, Jane E., Witt, Matthew J., Wright, Serena, Zilliacus, Kelly, Block, Barbara A., and Curnick, David J.

Subjects
Ecology
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

25. Do exotic salmonids feed on native fauna after escaping from aquaculture cages in Tasmania, Australia?

Author

Abrantes, Katya Gisela, Lyle, Jeremy Martin, Nichols, Peter D., and Semmens, Jayson Mark

Subjects
Tasmania -- Environmental aspects, Animal introduction -- Environmental aspects -- Food and nutrition, Earth sciences
Abstract

Atlantic salmon, Salmo salar, and rainbow trout, Oncorhynchus mykiss, are farmed in Tasmania, Australia, where fish sometimes escape into the natural environment. If escapees are able to survive and feed on native fauna, it is likely that they will have ecosystem impacts. Stomach content, body condition (muscle lipid content and Fulton' K), stable isotope, and fatty acid analysis were used to determine if escaped salmonids feed on native fauna. Results indicate that, in general, escaped salmonids do not feed on native fauna. Salmonids loose condition after escaping, and escapee stomachs were mostly empty or contained non-nutritious material or feed pellets. Nevertheless, almost a quarter of rainbow trout stomachs contained native fauna. The majority of escapees had biochemical composition similar to caged animals, indicating that these fish had not switched to feed on local food sources. However, a small fraction of escapees conclusively showed changes in biochemical parameters indicative of a shift to feeding on native fauna. Given the numbers and frequency of escapes, this can have an important impact on native species and on the ecology of Macquarie Harbour. On fait l'elevage du saumon atlantique, Salmo salar, et de la truite arc-en-ciel, Oncorhynchus mykiss, en Tasmanie, Australie, ou les poissons s'echappent parfois vers le milieu naturel. Si les poissons qui s'echappent reussissent a survivre et se nourrir de la faune indigene, il est vraisemblable qu'ils aient un impact sur l'ecosysteme. Nous avons determine les contenus stomacaux et la condition corporelle (contenu lipidique des muscles et K de Fulton) et analyse les isotopes stables et les acides gras afin de verifier si les salmonides echappes se nourrissaient de la faune indigene. Apres leur evasion, les poissons perdent de leur condition et les estomacs des poissons echappes sont en majorite vides ou alors contiennent du materiel non nutritif ou des granules alimentaires. Neanmoins, presque un quart des estomacs de truites arc-en-ciel contenait de la faune indigene. Les poissons echappes ont pour la plupart une composition biochimique semblable a celle des animaux encages, indiquant que ces poissons n'ont pas fait la transition vers les sources alimentaires locales. Cependant, une petite fraction des poissons echappes montre clairement des changements de variables biochimiques qui indiquent une transition vers l' alimentation a partir de la faune indigene. Etant donne le nombre et la frequence des fuites, cela peut avoir un impact important sur les especes indigenes et sur l'ecologie de Macquarie Harbour. [Traduit par la Redaction], Introduction Atlantic salmon, Salmo salar, and rainbow trout, Oncorhynchus mykiss, are native to the North Atlantic and North Pacific, respectively, and were introduced to Australia in the late 1800s as [...]

Published
2011
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28. Global spatial risk assessment of sharks under the footprint of fisheries

Author

Natural Environment Research Council (UK), Save Our Seas Foundation, European Commission, Fundação para a Ciência e a Tecnologia (Portugal), Fundação de Apoio à Pesquisa do Rio Grande do Norte, Xunta de Galicia, Australian Respiratory Council, Australian Institute of Marine Science, Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, Costa, Ivo da, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, McAuley, Rory, White, Timothy D., Block, Barbara A., Bradford, Russel W., Brooks, Annabelle, Cortés, Daniel Devia, Macena, Bruno C. L., Rogers, Paul J., Bessudo Lion, Sandra, Berumen, Michael L., Hazin, Fábio H. V., Marshall, Heather, Shillinger, George, Travassos, Paulo, Barnett, Adam, Carlisle, Aaron B., Harcourt, Robert, Campana, Steven E., Fischer, G. Chris, Bezerra, Natalia P. A., Brown, Judith, Doyle, Thomas K., Chapman, Demian D., Bond, Mark E., Southall, Emily J., Braun, Camrin D., Dagorn, Laurent, Richardson, Andrew J., Cochran, Jesse E. M., Bruce, Barry D., Goldsworthy, Simon D., Watanabe, Yuuki Y., Fowler, Mark, Chapple, Taylor K., Sheaves, Marcus, Bonfil, Ramón, Crochelet, Estelle C., Duarte, Carlos M., Brooks, Edward J., Ferreira, Luciana C., Quintero, Lina Maria, Smale, Malcolm J., Pierce, Simon J., Semmens, Jayson M., Ferretti, Francesco, Thums, Michele, Wetherbee, Bradley M., Gennari, Enrico, Forget, Fabian, Chisholm, John, Clarke, Christopher R., Stehfest, Kilian M., Drew, Michael, Klimley, Peter A., Peñaherrera-Palma, Cesar, Harman, Luke, Hammerschlag, Neil, Daly, Ryan, Poisson, Francois, Filmalter, John D., Duffy, Clinton A. J., Heard, Matthew, Erikson, Thor, Zárate, Patricia M., Hussey, Nigel E., Hearn, Alex R., Soria, Marc, Samoilys, Melita, Guttridge, Tristan L., Espinoza, Eduardo, Green, Jonathan R., Fitzpatrick, Richard, Gustafson, Johan A., Hueter, Robert E., Skomal, Gregory B., Patterson, Toby A., Simpson, Samantha J., Gollock, Matthew J., Kock, Alison A., Fontes, Jorges, Guzman, Hector M., Huveneers, Charlie, Lea, James S. E., Vandeperre, Frederic, Francis, Malcolm P., Gallagher, Austin J., Lana, Fernando O., Eguíluz, Víctor M., Pepperell, Julian G., Tolotti, Mariana T., Jewell, Oliver J. D., Meekan, Mark G., Nelson, Emily R., Singh, Sarika, Joyce, Warran, MacDonnell, Anna, Johnson, Ryan, McAllister, Jaime D., Ketchum, James T., Blaison, Antonin V., Holdsworth, John C., Meÿer, Michael A., Jordan, Lance K. B., Holmes, Bonnie J., Thorrold, Simon R., Howey, Lucy A., Keating Daly, Clare A., Bernal, Diego, Jorgensen, Salvador J., Ladino, Felipe, Hoyos, Hoyos, Rowat, David R. L., Sims, David W., Shivji, Mahmood, Morris, John J., Irion, David T., Llewellyn, Fiona, Arauz, Randall, Stevens, John D., Araujo, Gonzalo, Jacoby, David M. P., Tyminski, John P., Papastamatiou, Yannis P., Bach, Pascal, Soler, German, Lyon, Warrick S., Rohner, Christoph A., Sousa, Lara L., Weber, Sam B., Byrne, Michael E., Afonso, Pedro, Koen, Pieter, Acuña-Marrero, David, Towner, Alison, Afonso, André S., Irigoien, Xabier, Williams, Sean, Hays, Graeme C., Snyders, Laurenne B., Clua, Eric, Anders, Darrell, Vaudo, Jeremy J., Natural Environment Research Council (UK), Save Our Seas Foundation, European Commission, Fundação para a Ciência e a Tecnologia (Portugal), Fundação de Apoio à Pesquisa do Rio Grande do Norte, Xunta de Galicia, Australian Respiratory Council, Australian Institute of Marine Science, Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, Costa, Ivo da, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, McAuley, Rory, White, Timothy D., Block, Barbara A., Bradford, Russel W., Brooks, Annabelle, Cortés, Daniel Devia, Macena, Bruno C. L., Rogers, Paul J., Bessudo Lion, Sandra, Berumen, Michael L., Hazin, Fábio H. V., Marshall, Heather, Shillinger, George, Travassos, Paulo, Barnett, Adam, Carlisle, Aaron B., Harcourt, Robert, Campana, Steven E., Fischer, G. Chris, Bezerra, Natalia P. A., Brown, Judith, Doyle, Thomas K., Chapman, Demian D., Bond, Mark E., Southall, Emily J., Braun, Camrin D., Dagorn, Laurent, Richardson, Andrew J., Cochran, Jesse E. M., Bruce, Barry D., Goldsworthy, Simon D., Watanabe, Yuuki Y., Fowler, Mark, Chapple, Taylor K., Sheaves, Marcus, Bonfil, Ramón, Crochelet, Estelle C., Duarte, Carlos M., Brooks, Edward J., Ferreira, Luciana C., Quintero, Lina Maria, Smale, Malcolm J., Pierce, Simon J., Semmens, Jayson M., Ferretti, Francesco, Thums, Michele, Wetherbee, Bradley M., Gennari, Enrico, Forget, Fabian, Chisholm, John, Clarke, Christopher R., Stehfest, Kilian M., Drew, Michael, Klimley, Peter A., Peñaherrera-Palma, Cesar, Harman, Luke, Hammerschlag, Neil, Daly, Ryan, Poisson, Francois, Filmalter, John D., Duffy, Clinton A. J., Heard, Matthew, Erikson, Thor, Zárate, Patricia M., Hussey, Nigel E., Hearn, Alex R., Soria, Marc, Samoilys, Melita, Guttridge, Tristan L., Espinoza, Eduardo, Green, Jonathan R., Fitzpatrick, Richard, Gustafson, Johan A., Hueter, Robert E., Skomal, Gregory B., Patterson, Toby A., Simpson, Samantha J., Gollock, Matthew J., Kock, Alison A., Fontes, Jorges, Guzman, Hector M., Huveneers, Charlie, Lea, James S. E., Vandeperre, Frederic, Francis, Malcolm P., Gallagher, Austin J., Lana, Fernando O., Eguíluz, Víctor M., Pepperell, Julian G., Tolotti, Mariana T., Jewell, Oliver J. D., Meekan, Mark G., Nelson, Emily R., Singh, Sarika, Joyce, Warran, MacDonnell, Anna, Johnson, Ryan, McAllister, Jaime D., Ketchum, James T., Blaison, Antonin V., Holdsworth, John C., Meÿer, Michael A., Jordan, Lance K. B., Holmes, Bonnie J., Thorrold, Simon R., Howey, Lucy A., Keating Daly, Clare A., Bernal, Diego, Jorgensen, Salvador J., Ladino, Felipe, Hoyos, Hoyos, Rowat, David R. L., Sims, David W., Shivji, Mahmood, Morris, John J., Irion, David T., Llewellyn, Fiona, Arauz, Randall, Stevens, John D., Araujo, Gonzalo, Jacoby, David M. P., Tyminski, John P., Papastamatiou, Yannis P., Bach, Pascal, Soler, German, Lyon, Warrick S., Rohner, Christoph A., Sousa, Lara L., Weber, Sam B., Byrne, Michael E., Afonso, Pedro, Koen, Pieter, Acuña-Marrero, David, Towner, Alison, Afonso, André S., Irigoien, Xabier, Williams, Sean, Hays, Graeme C., Snyders, Laurenne B., Clua, Eric, Anders, Darrell, and Vaudo, Jeremy J.

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

30. A global perspective on the trophic geography of sharks

Author

Bird, Christopher S., Verissimo, Ana, Magozzi, Sarah, Abrantes, Katya G., Aguilar, Alex, Al-reasi, Hassan, Barnett, Adam, Bethea, Dana M., Biais, Gerard, Borrell, Asuncion, Bouchoucha, Marc, Boyle, Mariah, Brooks, Edward J., Brunnschweiler, Juerg, Bustamante, Paco, Carlisle, Aaron, Catarino, Diana, Caut, Stephane, Cherel, Yves, Chouvelon, Tiphaine, Churchill, Diana, Ciancio, Javier, Claes, Julien, Colaco, Ana, Courtney, Dean L., Cresson, Pierre, Daly, Ryan, De Necker, Leigh, Endo, Tetsuya, Figueiredo, Ivone, Frisch, Ashley J., Hansen, Joan Holst, Heithaus, Michael, Hussey, Nigel E., Iitembu, Johannes, Juanes, Francis, Kinney, Michael J., Kiszka, Jeremy J., Klarian, Sebastian A., Kopp, Dorothee, Leaf, Robert, Li, Yunkai, Lorrain, Anne, Madigan, Daniel J., Maljkovic, Aleksandra, Malpica-cruz, Luis, Matich, Philip, Meekan, Mark G., Menard, Frederic, Menezes, Gui M., Munroe, Samantha E. M., Newman, Michael C., Papastamatiou, Yannis P., Pethybridge, Heidi, Plumlee, Jeffrey D., Polo-silva, Carlos, Quaeck-davies, Katie, Raoult, Vincent, Reum, Jonathan, Torres-rojas, Yassir Eden, Shiffman, David S., Shipley, Oliver N., Speed, Conrad W., Staudinger, Michelle D., Teffer, Amy K., Tilley, Alexander, Valls, Maria, Vaudo, Jeremy J., Wai, Tak-cheung, Wells, R. J. David, Wyatt, Alex S. J., Yool, Andrew, Trueman, Clive N., Bird, Christopher S., Verissimo, Ana, Magozzi, Sarah, Abrantes, Katya G., Aguilar, Alex, Al-reasi, Hassan, Barnett, Adam, Bethea, Dana M., Biais, Gerard, Borrell, Asuncion, Bouchoucha, Marc, Boyle, Mariah, Brooks, Edward J., Brunnschweiler, Juerg, Bustamante, Paco, Carlisle, Aaron, Catarino, Diana, Caut, Stephane, Cherel, Yves, Chouvelon, Tiphaine, Churchill, Diana, Ciancio, Javier, Claes, Julien, Colaco, Ana, Courtney, Dean L., Cresson, Pierre, Daly, Ryan, De Necker, Leigh, Endo, Tetsuya, Figueiredo, Ivone, Frisch, Ashley J., Hansen, Joan Holst, Heithaus, Michael, Hussey, Nigel E., Iitembu, Johannes, Juanes, Francis, Kinney, Michael J., Kiszka, Jeremy J., Klarian, Sebastian A., Kopp, Dorothee, Leaf, Robert, Li, Yunkai, Lorrain, Anne, Madigan, Daniel J., Maljkovic, Aleksandra, Malpica-cruz, Luis, Matich, Philip, Meekan, Mark G., Menard, Frederic, Menezes, Gui M., Munroe, Samantha E. M., Newman, Michael C., Papastamatiou, Yannis P., Pethybridge, Heidi, Plumlee, Jeffrey D., Polo-silva, Carlos, Quaeck-davies, Katie, Raoult, Vincent, Reum, Jonathan, Torres-rojas, Yassir Eden, Shiffman, David S., Shipley, Oliver N., Speed, Conrad W., Staudinger, Michelle D., Teffer, Amy K., Tilley, Alexander, Valls, Maria, Vaudo, Jeremy J., Wai, Tak-cheung, Wells, R. J. David, Wyatt, Alex S. J., Yool, Andrew, and Trueman, Clive N.

Abstract

Sharks are a diverse group of mobile predators that forage across varied spatial scales and have the potential to influence food web dynamics. The ecological consequences of recent declines in shark biomass may extend across broader geographic ranges if shark taxa display common behavioural traits. By tracking the original site of photosynthetic fixation of carbon atoms that were ultimately assimilated into muscle tissues of 5,394 sharks from 114 species, we identify globally consistent biogeographic traits in trophic interactions between sharks found in different habitats. We show that populations of shelf-dwelling sharks derive a substantial proportion of their carbon from regional pelagic sources, but contain individuals that forage within additional isotopically diverse local food webs, such as those supported by terrestrial plant sources, benthic production and macrophytes. In contrast, oceanic sharks seem to use carbon derived from between 30° and 50° of latitude. Global-scale compilations of stable isotope data combined with biogeochemical modelling generate hypotheses regarding animal behaviours that can be tested with other methodological approaches.

Published
2018
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31. Effects of lipid and urea extraction on stable isotope values (δ13C and δ15N) of two batoids: A call for more species‐specific investigations.

Author

Crook, Kevin A., Barnett, Adam, Sheaves, Marcus, and Abrantes, Katya

Subjects
STABLE isotopes, UREA, LIPIDS, BLOOD plasma, FOOD chains
Abstract

The presence of lipids and urea in elasmobranch tissues can affect carbon (δ13C) and nitrogen (δ15N) stable isotope values, introducing bias in food web interpretations. Information on how lipids and urea affect δ13C/δ15N is only available for < 5% of ~ 1150 described elasmobranch species and results are highly variable among existing studies. Here, we investigate the effects of lipid and urea extraction on δ13C, δ15N, and C:N ratios in muscle and blood plasma of two batoids (Pastinachus ater and Himantura australis) and examine the influence of lipid/urea extraction on isotopic niche size and overlap. Lipid extraction (LE) did not affect δ13C, δ15N, or C:N ratios, suggesting low lipid content. Urea extraction (UE), however, increased δ15N and C:N in muscle. The ~ 1‰ δ15N increase represents a shift of ~ 0.5 trophic levels relative to bulk samples, highlighting the importance of UE to accurately assess trophic positions. Although there was no effect of any treatment on niche size, the probability of P. ater occurring within the niche of H. australis increased following UE. Overall, results suggest that urea should be removed from muscle prior to analysis, but LE is not required. Given the interspecific variability in the effects of lipid/urea on elasmobranch δ13C/δ15N, more studies are needed to assess the effects of lipid and urea on a broader range of species to produce a generalized understanding. Where no species‐specific data are available, we recommend pilot samples are analyzed to determine if LE is needed prior to preparation of the overall sample set. [ABSTRACT FROM AUTHOR]

Published
2019
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32. Importance of terrestrial subsidies for estuarine food webs in contrasting east African catchments

Author

Abrantes, Katya G., Barnett, Adam, Marwick, Trent R., Bouillon, Steven, Abrantes, Katya G., Barnett, Adam, Marwick, Trent R., and Bouillon, Steven

Abstract

Little is known on the degree to which terrestrial organic matter delivered to tropical estuaries contributes to estuarine consumers. Here, stable isotope analysis is used to constrain this contribution for contrasting east African estuaries whose catchments differ in relative C3/C4 vegetation cover. As these two types of vegetation differ strongly in δ13C, we anticipated that terrestrial subsidies would be reflected in a gradient in estuarine consumer δ13C values, following the relative importance of C3 (characterised by low δ13C) vs. C4 (characterised by high δ13C) cover. Five estuaries were sampled for aquatic biogeochemical parameters, primary producers and consumers of different trophic ecologies: the Zambezi (catchment with a C3/C4 cover of 61/39%) in Mozambique, the Tana in Kenya (36/64%) and the Betsiboka (42/58%), Rianila (85/15%) and Canal des Pangalanes (C3-dominated) in Madagascar. Sampling was done before and after the 2010/2011 wet season. There were positive relationships between the proportion of C4 cover in the catchment and turbidity, δ13CDIC, δ13CDOC, δ13CPOC and δ15NPN. There were also significant positive relationships between δ13CPOC and consumer δ13C and between δ15NPN and consumer δ15N for all consumer trophic guilds, confirming the incorporation of organic material transported from the catchments by estuarine consumers, and implying that this material is transported up to high trophic level fish. Bayesian mixing models confirmed that C4 material was the most important source for the highly turbid, C4-dominated estuaries, contributing up to 61–91% (95% CI) to phytodetritivorous fish in the Betsiboka, whereas for the less turbid C3-dominated estuaries terrestrial subsidies were not as important and consumers relied on a combination of terrestrial and aquatic sources. This shows that the ecology of the overall catchment affects the estuaries at the most basic, energet

Published
2013

33. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation

Author

Barnett, Adam, Abrantes, Katya G., Seymour, Jamie, Fitzpatrick, Richard, Barnett, Adam, Abrantes, Katya G., Seymour, Jamie, and Fitzpatrick, Richard

Abstract

Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (∼14 km away) and one grey reef shark completed a round trip of ∼250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

Published
2012

36. Estimating abundance and spatial distribution patterns of the bubble crabDotilla fenestrata(Crustacea: Brachyura).

Author

Flores, Augusto A. V., Abrantes, Katya G., and Paula, José

Subjects
*CRUSTACEA, *OCYPODIDAE, *CRABS, *INTERTIDAL zonation, *SEASHORE biology
Abstract

The bubble crabDotilla fenestrataforms very dense populations on the sand flats of the eastern coast of Inhaca Island, Mozambique, making it an interesting biological model to examine spatial distribution patterns and test the relative efficiency of common sampling methods. Due to its apparent ecological importance within the sandy intertidal community, understanding the factors ruling the dynamics ofDotillapopulations is also a key issue. In this study, different techniques of estimating crab density are described, and the trends of spatial distribution of the different population categories are shown. The studied populations are arranged in discrete patches located at the well-drained crests of nearly parallel mega sand ripples. For a given sample size, there was an obvious gain in precision by using a stratified random sampling technique, considering discrete patches as strata, compared to the simple random design. Density average and variance differed considerably among patches since juveniles and ovigerous females were found clumped, with higher densities at the lower and upper shore levels, respectively. Burrow counting was found to be an adequate method for large-scale sampling, although consistently underestimating actual crab density by nearly half. Regression analyses suggested that crabs smaller than 2.9 mm carapace width tend to be undetected in visual burrow counts. A visual survey of sampling plots over several patches of a largeDotillapopulation showed that crab density varied in an interesting oscillating pattern, apparently following the topography of the sand flat. Patches extending to the lower shore contained higher densities than those mostly covering the higher shore. Within-patch density variability also pointed to the same trend, but the density increment towards the lowest shore level varied greatly among the patches compared. [ABSTRACT FROM AUTHOR]

Published
2005
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