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4. Habitat driven responses of reef fish : temporal change, niche partitioning and selection

Author

Gouraguine, Adam

Subjects
570, QL Zoology
Abstract

Shallow water tropical and temperate marine habitats are changing dramatically in response to many stressor-driven effects. The change in turn threatens the associated fish communities relying on their maintenance for habitat provision. At present, a much better understanding of the interaction between changing habitats and the associated fish is necessary. To address the lack of understanding of the habitat – fish association, mechanisms which underpin the habitat driven responses of reef fish were examined, from entire communities down to species level, across tropical and temperate ecosystems. Using a highly biodiverse ecosystem as the model system, effects of changing habitat on the associated fish community were observed, consequently demonstrating how important, in terms of shelter and food resources, the overall habitat is in structuring the fish community. Furthermore, patterns of habitat use of certain fish species within and across tropical and temperate ecosystems were examined. Variation in the size of the habitat used and its overlap between species within systems, and uniform patterns in habitat use and comparable fish habitat size and overlap across systems, were discovered. By looking at fish habitat use within systems, invaluable knowledge was gained on ecological interactions between habitat and fish on a small scale. At the same time, detection of similar mechanisms of fish habitat use across ecosystems indicates to possible uniform response of fish communities to habitat change at a large-scale. Finally, by looking at fish habitat selection using olfaction, in a temperate model system, a range of subtle behavioural responses displayed during habitat selection were detected. These results highlighted the extent of complexity of the mechanisms used in fish habitat selection and the ubiquitous importance of the habitat and its properties for the associated fish. In addition to, and based on the ecological significance of the findings, a number of potential management and conservational applications of the research were given within the thesis.

Published
2018

13. Effects of fishing on the trophic structure of carnivorous fish assemblages from shallow rocky bottoms of the Mediterranean Sea and the temperate Atlantic Ocean.

Author

Cardona, Luis, Reñones, Olga, Gouraguine, Adam, Saporiti, Fabiana, Borrell, Asunción, Aguilar, Alex, and Moranta, Joan

Subjects
FISH populations, MARINE parks & reserves, OVERFISHING, FISHING, FISHERY laws, SIZE of fishes
Abstract

Here, we assess whether fishery exploitation affects the trophic structure of carnivorous fish. We censused fish and analysed the stable isotope ratios of C and N of species targeted by fishermen in areas open to fishing and marine protected areas (MPAs) in the Mediterranean Sea and the north-eastern Atlantic Ocean. Results demonstrated a major impact of fishing on the biomass and size structure of nektobenthic carnivorous fish. However, those changes did not modify the diversity of the trophic resources used by the assemblage, the pattern of resource partitioning between species, or the degree of trophic redundancy. These results add to recent evidence suggesting that MPAs implemented in fished seascapes may fail to restore the original structure of the food webs that once existed in pre-fished ecosystems because regional decimation and extinction of highly mobile predators prevent recovering the original diversity of predators at local scales, even in no-take areas. If so, more strict local fishing regulations are unlikely to restore the original diversity of high trophic level carnivores and restoration goals should be reframed in terms of an objective that is less unrealistic than restoring the pre-fished condition while still recovering aspects of the historical trophic structure. [ABSTRACT FROM AUTHOR]

Published
2023
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15. Transcending capitalism growth strategies for biodiversity conservation.

Author

Moranta, Joan, Torres, Cati, Murray, Ivan, Hidalgo, Manuel, Hinz, Hilmar, and Gouraguine, Adam

Subjects
SCIENTIFIC literature, BIODIVERSITY conservation, ENVIRONMENTAL degradation, BIODIVERSITY, CAPITALISM, ENVIRONMENTAL sciences, SUSTAINABLE development
Abstract

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2022
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20. Elasmobranch spatial segregation in the western Mediterranean

Author

Gouraguine, Adam, Hidalgo, Manuel, Moranta, Joan, Bailey, D.M., Ordines, Francesc, Guijarro, Beatriz, Valls-Mir, María, Barberá, Carmen, Quetglas, Antoni, de-Mesa, Aina, CEES - Student Awards Agency - Instituto Español de Oceanografía (Centre Oceanogràfic de Balears) - Marie Curie Intra-Euro- pean fellowship (IEF, FP7-PEOPLE-IEF-2008, Euro- pean Commission, and project No 236549)

Subjects
0106 biological sciences, Elasmobranch, Balearic Islands, GAM, MDS, community descriptors, species distribution, bathymetric patterns, spatial segregation, fishing impact, Elasmobranquios, impacto pesquero, SH1-691, segregación espacial, patrones batimétricos, Aquatic Science, Oceanography, Spatial distribution, 010603 evolutionary biology, 01 natural sciences, lcsh:Aquaculture. Fisheries. Angling, distribución de las especies, Centro Oceanográfico de Baleares, Mediterranean sea, Abundance (ecology), Aquaculture. Fisheries. Angling, Islas Baleares, descriptores de la comunidad, 14. Life underwater, Pesquerías, lcsh:SH1-691, Biomass (ecology), Ecology, 010604 marine biology & hydrobiology, Geography, Habitat, Spatial ecology, Ordination, Global biodiversity
Abstract

Basic information on the distribution and habitat preferences of ecologically important species is essential for their management and protection. This study focuses on the depth related trends and the geographic patterns that shape the community of the elasmobranch species in the Balearic Islands (Mediterranean Sea) using data collected from 2001 to 2009. Non-metric Multi-Dimensional Scaling (MDS) ordination was used to detect zonation patterns in the community. Generalized Additive Models (GAMs) were applied to analyse spatial and temporal variation in elasmobranch community descriptors (abundance, biomass, mean fish weight, number of species and diversity), as well as the abundance and mean length of the four individual species (S. canicula, G. melastomus, R. clavata, R. miraletus). Depth was the main factor determining the assemblage composition, and the MDS analysis identified four main groups with 60% of the similarity found to correspond to the continental shelf, shelf break, upper slope and middle slope of the surveyed area. GAM analysis identified spatial patterns that were independent of the bathymetric distribution preference. Although depth was a strong predictor for all the analyses performed, the geographic variation in the elasmobranch abundance was also important. The results also show a reduction in the mean length of the elasmobranch species in the areas with high fishing intensity. Our study evidences a clear spatial segregation of the main species throughout the ontogeny because the geographic and bathymetric effects were highly size dependent, with clear differences between the bathymetric distributions of juveniles and adults but no clear spatial overlapping. This study sheds new light on the spatial distribution of the elasmobranch species off the Balearic Islands, which is essential information for protecting marine organisms along with their habitats and promoting ecosystem based management., El conocimiento sobre la distribución y los hábitats preferentes de las especies clave del ecosistema es esencial para su gestión y protección. Este estudio se centra en el análisis de las tendencias batimétricas y los patrones de distribución geográfica que determinan la estructura de la comunidad de elasmobranquios de las Islas Baleares (Mar Mediterráneo), utilizando datos obtenidos entre los años 2001 y 2009. Los patrones de zonación de la comunidad se analizaron mediante análisis multidimensional de escala no métrico (MDS). La variación espacio-temporal de los descriptores de la comunidad de elasmobranquios (abundancia, biomasa, peso promedio, número de las especies y diversidad), y la abundancia y la talla media de cuatro especies (S. cani- cula, G. melastomus, R. clavata, R. miraletus) se analizaron mediante modelos generales aditivos (GAMs). La profundidad fue el factor más importante que determinó la composición de la comunidad y el análisis MDS identificó cuatro grupos principales de especies con un 60% de similitud, que se relacionaron con la plataforma continental, el final de la plataforma, el talud superior y el talud medio. Mediante los análisis GAM se identificaron los patrones de distribución espacial con in- dependencia de la distribución batimétrica preferente. Aunque la profundidad fue la variable dominante en todos los análisis considerados, la variabilidad geográfica en la abundancia total de elasmobranquios también fue significativa. Los resultados demuestran una reducción de la talla media de las especies de elasmobranquios en las zonas con mayor intensidad de pesca. Este estudio indica la existencia de una segregación ontogénica de las principales especies ya que las variaciones geográficas y batimétricas fueron dependientes de la talla, con claras diferencias entre la distribución batimétrica de los juveniles y los adultos, pero sin un solapamiento espacial obvio. Este estudio aporta nueva información sobre la distribución espacial de las especies de elasmobranquios en las Islas Baleares, mejora el conocimiento que se requiere actualmente para la protección de los organismos y hábitats marinos, y promueve la gestión basada en el ecosistema.

Published
2011
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