Distribution and abundance of post-larvae and juveniles of the Patagonian sprat, Sprattus fuegensis, and related hydrographic conditions

Sánchez, R.P; Remeslo, A. V.; Madirolas, Adrián; Ciechomski, J.D

doi:10.1016/0165-7836(94)00339-x

Cited by 46 publications

(25 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Magellanic Penguins Spheniscus magellanicus breeding at Martillo Island feed exclusively on Fuegian Sprat Sprattus fuegensis in years of abundance, which was the case during the study period, while relying on other prey species when sprats are scarce (Schiavini et al 2005;Scioscia et al, unpublished data). Sprat distribution is thought to be related to water masses ranging between 9 and 12°C (Sanchez et al 1995), which could be confirmed by the temperature profile recorded during the trips in our study (between 8 and 9°C), while in poor sprat years the temperatures range between 6 and 7°C (Raya Rey unpublished data, breeding season 2007/2008). Furthermore, waters in the Beagle Channel were well mixed, evident from only little variation (\0.5°C) in the temperature depth profiles obtained (Antezana 1999; this study) Also, sprats seem to be concentrated in certain areas of the Beagle Channel, although bathymetry was not found to be a key feature explaining sprat distribution, which coincided with the previous knowledge from an acoustic survey (Casarsa 2005).…”

Section: Influence Of Tidal Activitysupporting

confidence: 70%

Foraging movements of Magellanic Penguins Spheniscus magellanicus in the Beagle Channel, Argentina, related to tide and tidal currents

et al. 2010

View full text Add to dashboard Cite

This study investigates the movements of Magellanic Penguins Spheniscus magellanicus breeding on Isla Martillo during the early chick-rearing period. Foraging paths were reconstructed using GPS loggers that registered the penguins 0 geographic position, water temperature and depth at regular intervals. The relationship between penguins 0 movements and search strategies, tide and tidal currents were assessed. Mean trip duration was on average 14.7 ± 6.9 h (33% overnight), and the maximum distance reached was 24 ± 10 km. All penguins studied foraged to the east of the colony. We identified three phases based on the sinuosity and speed of the trajectory: transit, central and return. Foraging effort was higher during the central phase, followed by the transit phase, and lower in the return phase. Foraging success, measured as the percentage of time at the bottom during each phase, was also highest during the central phase. In all birds studied, the central phase of the foraging trip took place during ebb tide, and birds travelled to the foraging areas with flow tide running in the same direction of displacement. Our study suggests that penguins take advantage of tidal currents to facilitate their movements to and from the main foraging area, thereby reducing the energy expended. Moreover, we suggest that piscivorous diving birds may enhance their catch rate during ebb tide when fish are more concentrated near the channel bed.

show abstract

Section: Influence Of Tidal Activitysupporting

confidence: 70%

Foraging movements of Magellanic Penguins Spheniscus magellanicus in the Beagle Channel, Argentina, related to tide and tidal currents

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Falkland sprat forms dense schools in straits and channels along the Argentinean Patagonian coast (Sánchez et al 1995) and recently it has been identified south 41°S in the Pacific Ocean (Aranis et al 2007). It is a partial spawner whose reproductive activity tends to concentrate between September and October (Leal et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Larval fish distribution, growth and feeding in Patagonian fjords: potential effects of freshwater discharge

et al. 2011

View full text Add to dashboard Cite

In fjord systems, freshwater inputs occur by ice melting and river discharge, affecting seawater salinity along fjord and adjacent waters, and potentially the ecology of early life stages of marine fish occurring in the area. During austral spring 2008, a bio-oceanographic cruise was carried out in southern Chile between 47°00′ and 50°09′S, an area influenced by Baker River discharge and ice melting of Northern and Southern Ice Fields, the largest glaciers from Patagonia. Surface salinity and temperature ranged from 1.22 to 32.80, and from 8.11 to 10.68°C, respectively. Larval lightfish Maurolicus parvipinnis (Sternoptychidae) and Falkland sprat Sprattus fuegensis (Clupeidae) were the dominant species, with abundances of 2.2-39.9 larvae 10 m −2 and 3.4-77.1 larvae 10 m −2 , respectively. Postflexion stages of both species were collected mainly in surface density fronts. Otolith-based growth analyses estimated linear growth rates of 0.136 mm day −1 for M. parvipinnis of 4.1-15.1 mm, and 0.448 mm day −1 for S. fuegensis of 5.4-20.5 mm. Recent Otolith Growth Index (ROGI), based on the residual analysis of the relationship between increment width of outermost five microincrements and otolith radius, indicates that larval M. parvipinnis collected in low salinity waters showed a reduction of its recent growth rate compared those collected in saltier waters. Also, ROGI was positively correlated with salinity of the water column for larval M. parvipinnis. Gut content analysis showed that large larvae collected near sources of freshwater had lower number of prey in its guts and preyed on different items than fish larvae collected in saltier waters. Therefore, freshwater inputs from rivers and glaciers from Patagonia affected horizontal distribution, recent growth and feeding of larval fish in fjords and channels of southern Chile.

show abstract

“…There was an unidentified clupeid in the diet at Diego Ramirez in (Arata and Xavier, 2003, and a small unidentified fish at New Island in 1987 that made up 80% of the fish prey (Thompson, 1992), which may have been sprat. This species has a high biomass across the southern Patagonian shelf as far as the Magellan Strait (Sánchez et al, 1995), Chilean channel waters (Diez et al, 2012) and around the Falkland Islands (Agnew, 2002), and is common in the diet of other seabirds and The hierarchical clustering of albatross diet and fishery catch data by month, based on the proportion of sequences (RRA, black text) and proportion of catch (blue text). Clusters were based on dissimilarity indices calculated with the Manhattan method, and hierarchical clustering was constructed using the average agglomeration method (note low sample sizes during January 2014 and 2015).…”

Section: Fish Prey Diversitymentioning

confidence: 99%

DNA Metabarcoding as a Marine Conservation and Management Tool: A Circumpolar Examination of Fishery Discards in the Diet of Threatened Albatrosses

et al. 2017

View full text Add to dashboard Cite

Almost all of the world's fisheries overlap spatially and temporally with foraging seabirds, with impacts that range from food supplementation (through scavenging behind vessels), to resource competition and incidental mortality. The nature and extent of interactions between seabirds and fisheries vary, as does the level and efficacy of management and mitigation. Seabird dietary studies provide information on prey diversity and often identify species that are also caught in fisheries, providing evidence of linkages which can be used to improve ecosystem based management of fisheries. However, species identification of fish can be difficult with conventional dietary techniques. The black-browed albatross (Thalassarche melanophris) has a circumpolar distribution and has suffered major population declines due primarily to incidental mortality in fisheries. We use DNA metabarcoding of black-browed albatross scats to investigate their fish prey during the breeding season at six sites across their range, over two seasons. We identify the spatial and temporal diversity of fish in their diets and overlaps with fisheries operating in adjacent waters. Across all sites, 51 fish species from 33 families were identified, with 23 species contributing >10% of the proportion of samples or sequences at any site. There was extensive geographic variation but little inter-annual variability in fish species consumed. Several fish species that are not easily accessible to albatross, but are commercially harvested or by-caught, were detected in the albatross diet during the breeding season. This was particularly evident at the Falkland Islands and Iles Kerguelen where higher fishery catch amounts (or discard amounts where known) corresponded to higher occurrence of these species in diet samples. This study indicates ongoing McInnes et al. Fishery Discards in Albatross Diets interactions with fisheries through consumption of fishery discards, increasing the risk of seabird mortality. Breeding success was higher at sites where fisheries discards were detected in the diet, highlighting the need to minimize discarding to reduce impacts on the ecosystem. DNA metabarcoding provides a valuable non-invasive tool for assessing the fish prey of seabirds across broad geographic ranges. This provides an avenue for fishery resource managers to assess compliance of fisheries with discard policies and the level of interaction with scavenging seabirds.

show abstract

Distribution and abundance of post-larvae and juveniles of the Patagonian sprat, Sprattus fuegensis, and related hydrographic conditions

Cited by 46 publications

References 6 publications

Foraging movements of Magellanic Penguins Spheniscus magellanicus in the Beagle Channel, Argentina, related to tide and tidal currents

Foraging movements of Magellanic Penguins Spheniscus magellanicus in the Beagle Channel, Argentina, related to tide and tidal currents

Larval fish distribution, growth and feeding in Patagonian fjords: potential effects of freshwater discharge

DNA Metabarcoding as a Marine Conservation and Management Tool: A Circumpolar Examination of Fishery Discards in the Diet of Threatened Albatrosses

Contact Info

Product

Resources

About