Callier, M. D., Lefebvre, S., Dunagan, M. K., Bataille, M. P., Coughlan, J., & Crowe, T. P. (2013). Shift in benthic assemblages and organisms diet at salmon farms: community structure and stable isotope analyses. Marine Ecology Progress Series, 483, 153–167.
Résumé: ABSTRACT: The extent of the influence of salmon farming on the environment and on the uptake of particulate and dissolved effluents by benthic organisms was assessed using community structure and stable isotope analyses. Sediment cores were collected in 2 directions: perpendicular and parallel to the main residual current, 0, 25 and 200 m from 2 salmon farms (Millstone and Cranford) located in Mulroy Bay, Ireland. In addition, artificial substrates were placed for 2 mo at 1 m depth 0, 25 and 200 m from one farm to trace the uptake of farm-related nutrients by fouling organisms. The extent of measurable change in benthic communities (abundance, diversity, structure, trophic composition) depended on residual current direction. Intraspecific variation in isotopic values in benthic invertebrates was mostly explained by distance from cages. Organisms collected at impacted sites exhibited a shift in isotopic composition towards that of farm wastes. A shift in δ13C was observed in several invertebrates, including the polychaetes Malacoceros fuliginosus and Nephtys hombergii, Nematoda and the anemone Anthopleura balii. Fouling communities collected on artificial structures, mainly composed of the tunicate Ascidiella aspersa, showed higher δ15N values at fish cage sites compared to sites 200 m away. The study demonstrated that fish effluents were assimilated and became food sources for several organisms.
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Bijoux, J. P., Dagorn, L., Berke, G., Cowley, P. D., Soria, M., Gaertner, J. C., et al. (2013). Temporal dynamics, residency and site fidelity of spawning aggregations of a herbivorous tropical reef fish Siganus sutor. Marine Ecology Progress Series, 475, 233–247.
Résumé: ABSTRACT: The shoemaker spinefoot Siganus sutor is a fast-growing, short-lived, gonochorist and herbivorous reef fish that forms transient fish spawning aggregations (FSAs). In the Seychelles, FSAs of this species occur monthly between September and June around the full moon. To study the spawning aggregation dynamics of S. sutor, 39 reproductively active individuals were acoustically tagged and monitored at 3 known FSA sites (Paté Polite, Paté Désiré and Paté Dividi) off the west coast of Praslin island (Seychelles) between October 2010 and April 2011. The presence and absence of tagged fish at the 3 sites were monitored using moored arrays of passive acoustic receivers, while the density of fish at the FSAs was quantified using underwater visual census (UVC). Most tagged fish (87.0%) detected in more than 1 spawning period showed fidelity to single spawning sites. Predominantly, tagged individuals arrived at FSA sites at dawn and departed at dusk. Spawning residency times at FSA sites ranged from 0.02 to 16.1 d. At Paté Polite, residency times were higher in the first half of the spawning season. Residency times were often several-fold shorter than aggregation duration which, when combined with patterns in arrival and departure times, indicates high turnover of fish within aggregations. The findings of this study provide information needed for emerging co-management schemes that aim to sustain this socio-economically important fishery.
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Lezama-Ochoa, A., Ballón, M., Woillez, M., Grados, D., Irigoien, X., & Bertrand, A. (2011). Spatial patterns and scale-dependent relationships between macrozooplankton and fish in the Bay of Biscay: an acoustic study. Marine Ecology Progress Series, 439, 151–168.
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Peckham, S. H., Maldonado-Diaz, D., Tremblay, Y., Ochoa, R., Polovina, J., Balazs, G., et al. (2011). Demographic implications of alternative foraging strategies in juvenile loggerhead turtles Caretta caretta of the north Pacific Ocean. Marine Ecology Progress Series, 425, 269–280.
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