Pacific Sand Lance Ammodytes Hexapterus Research Articles

Quantifying spatiotemporal variation of nearshore forage fish schools with aerial surveys in Prince William Sound, Alaska

AbstractObjectiveChanges in abundance and distribution of schooling forage fish, such as the Pacific Sand Lance Ammodytes hexapterus and Pacific Herring Clupea pallasii, can be difficult to document using traditional boat‐based methods, especially in the shallow, nearshore habitats frequented by these species. In contrast, nearshore fish schools are easily observed and quantified from aircraft when light and sea conditions are favorable. We used aerial shoreline surveys to assess interannual variability in the distribution and abundance of schooling forage fish in Prince William Sound, Alaska, during the summers of 2010 and 2012–2022.MethodsDuring the surveys, aerial observers classified fish schools by their size, species, and (in some cases) age‐class. All observations were georeferenced along the flight path, converted to estimated surface area (m2) based on school diameter, and standardized by effort (shoreline kilometers surveyed).ResultPacific Herring were widely distributed, and school densities varied annually; there were several spikes in school density of up to 54.38 m2/km interspersed among years of lower average densities (7.73–25.57 m2/km). In contrast, Pacific Sand Lance were usually limited in their distribution to a few predictable locations. School density in these consistent areas varied across years, from a high of 50.98 m2/km in 2010 to a low of 0.15 m2/km in 2017. We validated 88 schools during aerial surveys conducted in 2014–2016 and 2019–2022, of which 76 (86%) were correctly identified to species.ConclusionHere, we provide indices of Pacific Herring and Pacific Sand Lance school density over time in shallow nearshore coastal areas of Prince William Sound, Alaska. These indices were generated from aerial surveys, which offer an effective alternative to boat‐based surveys for tracking forage fish schools when they occur in shallow and nearshore coastal habitats.

The spring ichthyoplankton of pacific water off northern Kuril Islands

The aim of the work is assesment of the species composition and spatial distribution of spring ichthyoplankton in area off northern Kuril Islands.Material and methods. It is based on the data of ichthyoplankton sampling in 2011, 2015 and 2016 yrs, trawl surveys in 2011 and 2015, and hydrological surveys in 2015 and 2016 yrs. Maps of the fish distribution at various stages of ontogenesis were made. Cluster analysis was used to identify the structure of ichthyoplankton in the 2015 collections.Novelty. For the first time, data on ichthyoplankton collected by the SakhNIRO in the 2010s near the northern Kuril Islands are presented. The ichthyoplankton complexes of the spring 2015 are identified and their spatial location is shown.Results. Eggs and larvae of 26 fish species were identified in ichthyoplankton collection, 86 species of teleosts were noted in trawl catches. The dominant components of ichthyoplankton were the walleye pollock eggs Gadus chalcogrammus, the larvae of the Pacific sand lance Ammodytes hexapterus and the larvae of sculpins gen. Gymnocanthus. Most species abundant in ichthyoplankton were among the most significant in trawl catches. The maximum abundance of ichthyoplankton, more than 600 ind./m2, in the area of the Northern Kuril occurred at the beginning of May. The structure of ichthyoplankton in April-May of 2015–2016 was quite similar, at the level of 60–70%.Practical significance. Knowledge of the main spawning areas of commercial fish and the places of development of their early stages is an important component for making decisions on the rational use of biological resources.

ЭКОЛОГИЯ ПИТАНИЯ СИВУЧА С РЕПРОДУКТИВНОГО ЛЕЖБИЩА НА МЫСЕ КОЗЛОВА (ВОСТОЧНАЯ КАМЧАТКА)

We studied the Steller's sea lion Eumetopias jubatus feeding ecology based on undigested food items found in feces at the Kozlova Cape rookery, Eastern coast of Kamchatka Peninsula, in summers (2004 through 2008). Atka mackerel Pleurogrammus monopterygius and walleye pollock Theragra chalcogramma were dominant in a sea lion diet hauled out at Kozlova Cape rookery in terms of frequency of occurrence. Less frequently occurred were Pacific sand lance Ammodytes hexapterus, Threespine stickleback Gasterosteus aculaeatus, Smelt Osmerus mordax, Sculpins Cottidae, Pacific sandfish Trichodon trichodon, Flatfishes Pleuronectidae, Salmon Oncorhynchus sp., Pacific cod Gadus macrocephalus, and Squid and Octopus Cephalopoda. The contribution of the other food items was not significant. Diet diversity median during sea lion single foraging trip was two prey items, range being one to nine Atka mackerel and Walleye pollock as the major prey objects. Most of sea lion food items were referred to species featuring a marked seasonal presence near the shore or on the shelf. Sea lions feed near the rookery close to the shore on seasonal food aggregations common to the area. Seasonal prey aggregations can be extremely important for breeding animals due to increasing the efficiency of food search and capture, which in turn can affect the reproductive success of animals and their survival. In this regard, the stability of the food resource near Kozlova Cape Rookery may influence sea lion population status there.

Spatiotemporal Variation in Distribution, Size, and Relative Abundance within a Salish Sea Nearshore Forage Fish Community

AbstractForage fish are schooling species commonly occurring in both offshore pelagic and nearshore coastal habitats. Beyond use by some species for spawning, the dynamics of nearshore habitat use are not well understood. The objective of our study was to evaluate the spring–summer dynamics of forage fish occurrence in nearshore habitats of the Strait of Juan de Fuca, Washington. We suspected that habitat changes resulting from removal of two large dams on the Elwha River (2009–2011) may have altered fish presence and abundance. Monthly beach seine sampling in four regions along 40 km of shoreline was conducted from April to September between 2006 and 2019. We caught nearly 600,000 fish, comprising 82 different species. Nine species of forage fish accounted for 81.7% of all fishes caught; most were classified as postlarvae and juveniles based on size. There were spatial differences in the forage fish assemblage between two of our sites but no discernable year effects and no obvious impact of dam removal on forage community composition. Three species represented 78.8% of the catch: Pacific Herring Clupea pallasii, Pacific Sand Lance Ammodytes hexapterus, and Surf Smelt Hypomesus pretiosus. We used a Bayesian generalized linear mixed model to evaluate spatial and temporal variability in the probability of occurrence of these species. Each species exhibited a unique pattern of intra‐annual, interannual, and regional fluctuations. Pacific Herring occurrence progressively increased monthly, Pacific Sand Lance occurrence decreased, and Surf Smelt probability of occurrence peaked in June. Temporal variations in distribution and abundance of these species are likely driven by life history differences and biological requirements. We speculate that specific characteristics of each region, including proximity to spawning areas, spawn timing, extant current patterns, and ecosystem processes, drove variations in distribution between species.

Steller sea lion diet in the Eastern Kamchatka

We studied the diet of Steller sea lion (Eumetopias jubatus) on the eastern coast of Kamchatka based on the remains of undigested food parts found in feces at terrestrial sites near Cape Kozlova (rookery) and Cape Kekurny (haulout) in the summer. A total of 276 fecal samples were analyzed from 2004 to 2008. Forty eight food items of 17 fish families and one family of cephalopod mollusks were identified. Steller sea lion diet was diverse yet dominated by only several species. The pollock Gadus chalcogrammus, Atka mackerel Pleurogrammus monopterygius, Pacific sand lance Ammodytes hexapterus and Hemilepidotus sp. were dominant by frequency of occurrence in decreasing order at both sites. Differences were found in the Steller sea lion diet in the studied sites. Prey diversity at Kekurny Cape within scat samples ranged from one to twelve objects within the median of four prey item per a sample. The median of prey diversity at Kozlov Cape within scat samples was two food objects within a range of one to nine prey types per sample. Of the 37 scats (24,5 %) collected at Kozlov Cape that contained a single prey item, 75,7% contained Atka mackerel. Among scats collected at Kekurny Cape that contained a single prey species (n=10, 8,0 %), 50,0 % contained Atka mackerel and 40,0 % pollock. In contrast to the high diet diversity at Kekurny Cape haulout, breeding Steller sea lions at Kozlova Cape rookery fed on a narrow set of prey items. Interannual changes in the diet structure at each site were not statistically significant.

ЛЕТНЕЕ ПИТАНИЕ СИВУЧА В ВОДАХ ДАЛЬНЕГО ВОСТОКА РОССИИ В 2004–2008 ГОДАХ

The diet of Steller sea lion Eumetopias jubatus was studied based on undigested food parts found in feces collected in the summer season on 20 rookeries in the Russian Far East. A total of 915 samples were analyzed between 2004 and 2008, in which 65 food items were identified. The frequency of occurrence of 11 diet items was greater than 5%, including Atka mackerel Pleurogrammus monopterygius (64.8%), Pollock Theragra chalcogramma (44.3%), Pacific salmon Salmonidae (20.5%), Irish lord Hemilepidotus sp. (20.4%), Pacific sand lance Ammodytes hexapterus (15.8%), Pacific herring Clupea pallasi (9.5%), Squid and Octopus Cephalopoda (8.4%), Pacific cod Gadus macrocephalus (5, 9%), Pacific sandfish Trichodon trichodon (5.9%), Flatfishes Pleuronectidae (5.8%), Threespine stickleback Gasterosteus aculaeatus (4.9%). Three regions with different diets were identified – the Sea of Okhotsk, the Kuril Islands, and Kamchatka with the Commander Islands. In the Sea of Okhotsk, Pollock and Herring (83.6% by frequency of occurrence) dominated among undigested food remains in feces. The diet at the Kuril Islands rookeries was variable within the region. The general pattern was a low diversity of diet at each Kuril Island sites and predominance of 1-3 food items, probably the most accessible near the sites (Pollock, Squid and Octopus, Atka mackerel, Pacific salmon). The diet pattern in Kamchatka and the Commander Islands in the summer season was characterized by a high diet diversity. In contrast to other regions, the diet includes in high proportion small non-commercial species – Sand lance, Irish lord, Pacific sandfish, Flatfishes, Threespine stickleback and others. The regional patterns of sea lion diets show the spatial distribution and areas of abundant biomass of the main food items. The diet patterns of sea lions from rookeries differed from haulouts in having a higher content of abundant food items. Long-term changes in diet structure were not statistically significant.

Kelp Forest Zooplankton, Forage Fishes, and Juvenile Salmonids of the Northeast Pacific Nearshore

AbstractKelp forests are an important ecological component of temperate coastal systems that are sensitive to anthropogenic disturbance and are in decline in many locations globally. In the northeastern Pacific Ocean off the coast of Washington, USA, bull kelp Nereocystis luetkeana forests are seasonally used by juvenile salmonids and forage fishes; however, details on ecosystem functional linkages for forage fishes and salmonids are not well quantified. Using a zooplankton drop net and snorkel surveys for fishes, we sampled two bull kelp forests across multiple years. Our goal was to quantify differences in the communities of zooplankton, juvenile salmonids (Chinook Salmon Oncorhynchus tshawytscha and Coho Salmon O. kisutch), and forage fishes (Pacific Herring Clupea pallasii, Surf Smelt Hypomesus pretiosus, and Pacific Sand Lance Ammodytes hexapterus) between kelp forests and adjacent nonkelp (open‐water) habitats. We tested the hypothesis that zooplankton common in the diets of surface‐oriented forage fishes and juvenile salmonids would be more abundant in kelp than in open water. At the overall assemblage level of organization, kelp and open‐water habitats had similarly abundant and diverse zooplankton communities. However, decapods and phytal‐associated harpacticoid copepods within this assemblage (i.e., groups that are an important component of fish diets) were significantly more abundant in kelp forests than in open‐water habitat. Greater presence and abundance of zooplankton, juvenile salmonids, and forage fishes in kelp forests compared to adjacent open‐water habitats suggest that kelp forests are important for culturally and economically valuable forage fishes and salmonids and warrant further study to define and conserve their ecosystem function.

Особенности питания керчака-яока Myoxocephalus jaok (Cuvier, 1829) (Cottidae) и его место в трофической системе прикамчатских вод

По материалам 1978–2008 гг. (975 желудков обработано количественно-весовым методом, около 2 тыс. желудков вскрыто и проанализировано в полевых условиях) рассмотрены особенности питания керчака-яока Myoxocephalus jaok в прикамчатских водах Охотского, Берингова морей и Тихого океана и предпринята попытка выяснить место этого вида рогатковых в трофической системе данного района. Показано, что керчак-яок характеризуется широким спектром питания (свыше 100 кормовых объектов), однако наибольшее значение в его рационе имеют рыбы (в среднем 64,1 % массы пищи) и десятиногие раки (32,2 %). Основу первых составляют камбалы Pleuronectidae (24,3 % массы пищи), минтай Theragra chalcogramma (14,4 %), тихоокеанская песчанка Ammodytes hexapterus (9,5 %) и рогатковые Cottidae (5,6 %); вторых ― крабы семейства Majidae (22,4 %) (главным образом краб-стригун Chionoecetes opilio (14,2 %) и краб-паук Hyas coarctatus (8,1 %)), а также крабы семейства Atelecyclidae (4,7 %) (преимущественно пятиугольный волосатый краб Telmessus cheiragonus (4,5 %)) и креветки семейства Crangonidae (3,1 %). Рассмотрены сезонные, локальные, межгодовые и возрастные изменения состава пищи керчака-яока. Установлено, что этот вид является факультативным хищником-засадчиком; ему свойственна высокая пластичность питания, дающая возможность использовать значительный набор пищевых компонентов. В трофической системе прикамчатских вод выделены звенья, формирующие биомассу керчака-яока.

LONG-TERM AVERAGE BIOMASS AND DOMINANT FISH SPECIES IN THE BOTTOM BIOTOPES OF THE OKHOTSK SEA. PART 1. COMPOSITION AND QUANTITATIVE RATIO OF SPECIES ON SHELVES IN DIFFERENT AREAS OF THE SEA

Composition of the demersal fish community in the bottom biotopes of 14 biostatistical areas of the Okhotsk Sea is considered on the data of 9,189 standard trawl catches obtained in 95 expeditions conducted by Pacific Fish. Res. Center (TINRO) in 1977–2010. The most abundant fish species in each area are ranked by biomass. The total demersal fish biomass is estimated as 9583.0 . 103 t (2124.9 . 103 t without pollock and herring). The most numerous demersal species are: pacific cod Gadus macrocephalus, yellowfin sole Limanda aspera, pacific sand lance Ammodytes hexapterus, great sculpin Mycocephalus polyacanthocephalus, and saffron cod Eleginus gracilis.

Summer Ichthyoplankon in Onega Bay of the White Sea: Species Composition and Spatial Distribution

Data on the species composition and distribution of ichthyoplankton in Onega Bay of the White Sea are presented for June–July 2007, 2010–2012, and 2015–2016. In the ichthyoplankton, the specimens of the early developmental stages of 21 fish species were registered; the larvae of the White Sea herring Clupea pallasi marisalbi, capelin Mallotus villosus, and Pacific sand lance Ammodytes hexapterus were the most abundant. It is shown that the northwestern and southeastern zones, distinguished in Onega Bay by hydrophysical parameters, also differ in species composition and in ichthyoplankton abundance.

Introduction: Marine Harvesting in the Arctic

Abstract In a warmer Arctic, living conditions will change at all trophic levels of the marine ecosystem. Increased air and water temperatures will likely substantially reduce ice coverage. Trophic interactions might change and increased competition between resident Arctic species and invasive species seems likely. A theme session on “Marine harvesting in the Arctic” was held at the international Arctic Frontiers Conference in Tromsø, Norway, in January 2013. The theme session partitioned the topic into two sub-sessions: (i) introduced species, immigration and fate of resident species and (ii) prospective harvesting of marine biological resources in the Arctic. The four articles that follow this introduction are based on presentations made at the Arctic Frontiers theme session. These articles cover topics such as: how ice breeding seals (Pagophilus groenlandicus) can cope with ice retention in the Northwest Atlantic, how planktonic stages of the resident polar cod (Boreogadus saida) and the pole-ward expanding Pacific sand lance (Ammodytes hexapterus) may compete for food in the warming Beaufort Sea, and how the introduced red king crab (Paralithodes camtschaticus) disperse in the Barents Sea. The fourth article shows how differences in the life-history strategies of keystone zooplankton species will likely affect future productivity of commercial fisheries in polar regions.

Spatial and temporal variation in the diet of the Pacific sand lance Ammodytes hexapterus in waters off the coast of British Columbia, Canada

Variation in the diet of the Pacific sand lance Ammodytes hexapterus was examined in three years (2009-2011) at four sites in British Columbia, Canada. There were 12 major taxa of prey in diets, eight of which were Crustacea, with copepods being by far the dominant taxon in all 12 site-years. Of the 22 copepod taxa recorded, only Calanus marshallae and Pseudocalanus spp. occurred in all collections, and these two calanoid species dominated diets in terms of frequency of occurrence and total numbers of prey (Pseudocalanus spp. in most collections), and total prey biomass (C. marshallae in all collections). Based on an index of relative importance, C. marshallae was the primary prey at the two southerly sampling sites (Pine and Triangle Islands) and Pseudocalanus spp. at the two northerly sites (Lucy Island and S'Gang Gwaay). Based on an index of dietary overlap, the species composition of the copepod component of A. hexapterus diets overlapped very strongly at the northerly and the southerly pairs of sites in both a cold-water La Niña year (2009) and a warm-water El Niño year (2010), but overall there was more homogeneity amongst all four sites in the La Niña year.

Complete mitochondrial DNA sequence of the Pacific sand lance Ammodytes hexapterus (Perciformes: Ammodytidae): Mitogenomic perspective on the distinction of Ammodytes hexapterus and Ammodytes personatus

The complete mitochondrial genome of the Pacific sand lance Ammodytes hexapterus was determined. The entire sequence is 16,527 bp in length assembling 22 tRNAs, 2 rRNAs and 13 protein-coding genes as well as the putative control region and OL. The gene arrangement and component are identical to those of canonical vertebrate mitochondrial genomes. The length of 16S rRNA and the repetitive times of termination-associated sequence in control region could be a useful marker for the distinction of A. hexapterus and A. personatus.

Kittiwake diets and chick production signal a 2008 regime shift in the Northeast Pacific

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 477:271-284 (2013) - DOI: https://doi.org/10.3354/meps10161 Kittiwake diets and chick production signal a 2008 regime shift in the Northeast Pacific Scott A. Hatch* US Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, Alaska 99508, USA *Email: shatch.isrc@gmail.com ABSTRACT: I examined ~2700 food samples collected from adult and nestling black-legged kittiwakes Rissa tridactyla from 1978 through 2011 on Middleton Island in the Gulf of Alaska. The kittiwake diet was composed chiefly of fish, but invertebrates were taken in appreciable quantities in April and May. Upon spring arrival at the colony, adult kittiwakes foraged regularly at night on vertically migrating mesopelagic prey—lanternfishes (Myctophidae), squids, crustaceans, and polychaetes—a behavior they largely discontinued by egg-laying. During incubation and chick-rearing, food samples contained mostly (~85% by weight) Pacific sand lance Ammodytes hexapterus, capelin Mallotus villosus, Pacific herring Clupea pallasii, sablefish Anopoploma fimbria, krill (Euphausiidae), and juvenile salmon Onchorynchus gorboscha and O. keta. A salient finding over the longitudinal study was the emergence, twice, of capelin as a dominant forage species—once in 2000 to 2003, and again in 2008 through 2011. Kittiwakes responded to capelin availability by producing markedly higher numbers of fledged young. The 2000 to 2003 event corresponded to a previously documented shift to cooler conditions in the NE Pacific, which apparently was relatively limited in magnitude or duration. The more recent transition appears stronger and may be more lasting. I submit that 2008 was an important turning point, marking a substantive reversal of warm conditions that began with the well-documented regime shift of 1977. That interpretation is consistent with the existence of a ~60 yr cycle in ocean and atmospheric conditions in the North Pacific. All else being equal, it predicts the next 20 to 30 yr will be favorable for species such as kittiwakes and Steller sea lions, which seemed to respond negatively to the 1977 to 2007 warm phase of the Pacific Decadal Oscillation. KEY WORDS: Black-legged kittiwake · Steller sea lion · Forage fish · Capelin · Climate change · 60-year cycle · Pacific Decadal Oscillation · Prey relative occurrence Full text in pdf format Supplementary material PreviousNextCite this article as: Hatch SA (2013) Kittiwake diets and chick production signal a 2008 regime shift in the Northeast Pacific. Mar Ecol Prog Ser 477:271-284. https://doi.org/10.3354/meps10161 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 477. Online publication date: March 12, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Harbor seal diet in northern Puget Sound: implications for the recovery of depressed fish stocks

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 464:257-271 (2012) - DOI: https://doi.org/10.3354/meps09880 Harbor seal diet in northern Puget Sound: implications for the recovery of depressed fish stocks Monique M. Lance1,*, Wan-Ying Chang2, Steven J. Jeffries1, Scott F. Pearson3, Alejandro Acevedo-Gutiérrez4 1Washington Department of Fish and Wildlife, Wildlife Science Program, Lakewood, Washington 98498, USA 2National Science Foundation, Arlington, Virginia 22230, USA 3Washington Department of Fish and Wildlife, Wildlife Research Program, Olympia, Washington 98501, USA 4Department of Biology, Western Washington University, Bellingham, Washington 98225-9160, USA *Email: monique.lance@dfw.wa.gov ABSTRACT: Recovery of severely declining resource stocks often leads to enforced quotas or reduced human access to those resources. Predators, however, do not recognize such restrictions and may be attracted to areas of increased prey abundances where human extraction is being limited. Such targeting by predators may reduce or retard the potential recovery of depressed stocks. In the San Juan Islands, northern Puget Sound, USA, marine reserves were implemented to recover depressed fish populations. We examine the role of harbor seals Phoca vitulina in the San Juan Islands food web. We describe the temporal and spatial variability in their diet, emphasizing species for which reserves were established (rockfish Sebastes spp.) and other important depressed stocks, including salmon Oncorhynchus spp. and Pacific herring Clupea pallasii. During winter and spring, seals primarily consumed Pacific herring, Pacific sand lance Ammodytes hexapterus, northern anchovy Engraulis mordax, and walleye pollock Theragra chalcogramma. During summer/fall, adult salmonids composed >50% of the diet and were particularly important in odd-numbered calendar years, when pink salmon O. gorbuscha spawn. Rockfish were not a primary prey species at any time of the year, suggesting that the abundance of alternative prey species may reduce predation pressure and provide a critical buffer to rockfish predation. The importance of considering increased visitation by marine predators to areas where potential prey are enhanced through restrictions on human extractions should be considered when modeling the efficacy of quotas and reduced access areas, such as marine reserves. KEY WORDS: Harbor seal · Phoca vitulina · Marine reserves · Diet composition · Scat analysis · Pacific herring · Salmon · Rockfish Full text in pdf format PreviousNextCite this article as: Lance MM, Chang WY, Jeffries SJ, Pearson SF, Acevedo-Gutiérrez A (2012) Harbor seal diet in northern Puget Sound: implications for the recovery of depressed fish stocks. Mar Ecol Prog Ser 464:257-271. https://doi.org/10.3354/meps09880 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 464. Online publication date: September 19, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.

Diets and Trophic Linkages of Epipelagic Fish Predators in Coastal Southeast Alaska during a Period of Warm and Cold Climate Years, 1997–2011

AbstractThis study identifies important trophic links for epipelagic marine fish predators in Southeast Alaska to improve understanding of marine ecosystem dynamics in response to climate change. Fish predators can be viewed as autonomous samplers whose diets should integrate the available prey taxa commensurate with environmental conditions. We examined fish predators from annual (1997–2011) surveys conducted in May to September by the Southeast Coastal Monitoring (SECM) project of Auke Bay Laboratories in the marine waters of Southeast Alaska. This project has emphasized long‐term monitoring of strait and coastal marine habitats used by juvenile Pacific salmon Oncorhynchus spp. and associated epipelagic fishes to understand how environmental variation affects the sustainability of salmon resources. From 1,295 surface trawl hauls, trophic links were identified for 2,473 fish representing 19 predator species, principally adult and immature salmon, immature walleye pollock Theragra chalcogramma, and spiny dogfish Squalus acanthias. The most common fish prey consumed were fish larvae, juvenile salmon, Pacific herring Clupea pallasii, capelin Mallotus villosus, walleye pollock, lanternfishes (Myctophidae), and Pacific sand lance Ammodytes hexapterus, whereas the most common invertebrate prey consumed were euphausiids, decapod larvae, pteropods, and amphipods. This study describes the degree of piscivory, incidence of juvenile salmon prey, and frequency and weight composition of prey in the diets of epipelagic fish predators, but it did not clearly detect an effect of warm‐versus‐cold climate years on the diets of key planktivorous or piscivorous predators over the 15‐year time series. Identifying the persistence of trophic links in epipelagic waters over time is important because climate‐related changes in the upper water column have the potential to impact Southeast Alaska marine ecosystem dynamics and the productivity of important regional fisheries by altering key prey resources and trophic interactions.Received December 2, 2011; accepted May 9, 2012

Environmental control of the breeding success of rhinoceros auklets at Triangle Island, British Columbia

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 424:285-302 (2011) - DOI: https://doi.org/10.3354/meps08950 Environmental control of the breeding success of rhinoceros auklets at Triangle Island, British Columbia Gary Borstad1,*, William Crawford2, J. Mark Hipfner3, Richard Thomson2, Kim Hyatt4 1ASL Environmental Sciences Inc., Victoria, British Columbia, V8M 1Z5, Canada 2Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, V8L 4B2, Canada 3Environment Canada, RR#1 5421 Robertson Road, Delta, British Columbia, V4K 3N2, Canada 4Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, V8L 4B2, Canada *Email: gborstad@aslenv.com ABSTRACT: There are few studies of the mechanistic links between physical environmental processes and biotic responses in marine ecosystems that have strong predictive power. At Triangle Island, the largest seabird colony along Canada’s Pacific coast, annual breeding success of rhinoceros auklets Cerorhinca monocerata varies dramatically. Previous studies have correlated this variability with ocean temperature, but this relationship occasionally fails, suggesting that it is not causal. We used historical satellite data time series of sea surface temperature, chlorophyll, and winds to study the oceanography of this remote colony. We found that rhinoceros auklets bred more successfully when the spring transition in regional winds and the resulting spring phytoplankton bloom occurred early in April. These factors appear to control the annual recruitment of Pacific sandlance Ammodytes hexapterus, as measured by the percent by biomass of young-of-the-year sandlance in the nestling diet. These linkages imply bottom-up control in this system. Suggesting broader implications of our work, we also found that marine survival of economically and culturally important sockeye salmon Oncorhynchus nerka from nearby Smith Inlet was strongly correlated with the fledgling mass of the rhinoceros auklets, sandlance in the chicks’ diets, and regional chlorophyll in April. The timing of the spring wind transition and phytoplankton bloom appear to be important for other predators in this system. We think that these relationships with wind and chlorophyll derived from satellite data are potentially valuable explanatory tools that will be widely applicable to studies of early marine survival of many marine species. KEY WORDS: Rhinoceros auklet · Ocean chlorophyll · Ocean temperature · Wind · Satellite imagery · Sandlance · Salinity · Sockeye salmon · Triangle Island Full text in pdf format PreviousCite this article as: Borstad G, Crawford W, Hipfner JM, Thomson R, Hyatt K (2011) Environmental control of the breeding success of rhinoceros auklets at Triangle Island, British Columbia. Mar Ecol Prog Ser 424:285-302. https://doi.org/10.3354/meps08950 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 424. Online publication date: March 01, 2011 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2011 Inter-Research.

Do marine birds use environmental cues to optimize egg production? An experimental test based on relaying propensity

According to the environmental cues hypothesis, female birds use information available to them in the early‐season environment to fine‐tune egg production annually. However, support for the hypothesis derives largely from correlational studies. In each year from 2002 to 2006, which spanned a period of extreme variation in environmental conditions, we removed eggs from early‐laying rhinoceros auklets Cerorhinca monocerata, burrow‐nesting seabirds that lay a single‐egg clutch. We then measured their relaying rates, relaying intervals, and breeding success. We also monitored the timing and success of breeding in control pairs, and control chick diets. If the experimental females base their relaying decision on early‐season cues, then we predict that few will relay in years in which early‐laying control birds breed unsuccessfully, and in which a preferred prey species, Pacific sandlance Ammodytes hexapterus, is in short supply in nestling diets. Results matched neither prediction. In each year, almost all (88–90%) of the experimental females relaid, despite that the control pairs’ breeding success (32–87% fledged chicks), and their chicks’ diets (twofold variation in proportion of sandlance), varied markedly. We conclude that female rhinoceros auklets did not modify their relaying decision in response to variation in environmental conditions, although relaying intervals and their own breeding success (0–78%) covaried negatively. Our results may have important implications related to using seabirds as monitors of the marine environment.

Distribution and Use of Shallow‐Water Habitats by Pacific Sand Lances in Southeastern Alaska

AbstractThe Pacific sand lance Ammodytes hexapterus is an important prey species, but little is known about its distribution and habitat use, especially among early life stages in southeastern Alaska. To address this information need, we examined the distribution and habitat use of Pacific sand lances by sampling a variety of shallow‐water habitats (depth < 6 m) with a beach seine seasonally throughout southeastern Alaska from 1998 to 2006. An estimated 81,939 Pacific sand lances were captured at 31 of 49 locations and in 109 of 610 seine hauls. Total catch and percent frequency of occurrence (FO; [number of seine hauls with Pacific sand lances/total number of hauls] × 100) was greatest in summer (73,033 fish, FO = 21%), followed by spring (8,857 fish, 18%) and winter (49 fish, 1%). Pacific sand lances were captured in all habitat types; total catch in spring ranged from 16 fish in understory kelp (e.g., Laminariales) to 8,525 fish in bedrock outcrops, whereas total catch in summer ranged from 5,858 fish in sand to 54,851 fish in eelgrass Zostera marina. The FO was relatively consistent among the above habitat types and ranged from 15% to 20% in spring and from 15% to 35% in summer. Pacific sand lances use a variety of shallow‐water habitats for at least 4 months in spring and summer; habitat is not limited to sandy substrates for burrowing but also includes bedrock, eelgrass, and kelp as likely foraging areas. Age‐1 and younger Pacific sand lances dominated our catches; size range of captured fish was 39‐168 mm fork length. The importance of Pacific sand lances in the diets of other fishes, seabirds, and marine mammals justifies the need to better understand, protect, and manage habitats that are essential to Pacific sand lances.

Fish Assemblages in Shallow, Nearshore Habitats of the Bering Sea

AbstractThe Bering Sea provides over one‐half of U.S. fishery production, yet knowledge of the use of its shallow (<5 m), nearshore (<20 m from shore) waters by fish is limited. In June 2005, we sampled shallow, nearshore waters of the Bering Sea at three Aleutian islands with a beach seine to estimate the relative abundance and species distribution of fish. Three habitat types were sampled: Nonvegetated sand substrate, vegetated cobble substrate, and vegetated bedrock substrate. A total of 70 sites were seined on Akutan, Akun, and Unalaska islands. The total estimated catch was 83,910 fish representing 33 taxa. Five species comprised 98% of the total catch. Pacific sand lance Ammodytes hexapterus was the most abundant species; approximately 35,000 of these fish were captured, and they occurred in 60% of all seine hauls. The next most abundant fish were young‐of‐the‐year (age‐0) gadids (primarily walleye pollock Theragra chalcogramma), age‐0 pink salmon Oncorhynchus gorbuscha, age‐0 Pacific sandfish Trichodon trichodon, and snake prickleback Lumpenus sagitta. Fish were unequally distributed among habitats. The estimated mean catch per seine haul was 1,171 fish in sand sites, 1,647 fish in cobble sites, and 79 fish in bedrock sites. Most Pacific sand lances (98%) were captured in sand sites, whereas most gadids (97%), pink salmon (80%), Pacific sandfish (96%), and snake pricklebacks (99%) were caught in cobble sites. Sand and cobble nearshore habitats in the Bering Sea provide important habitat for many fish species in summer, especially forage fish.