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Fishes in the Gulf of Maine
... Based on fish age-size relationships for the four taxa, the smallest fishes we measured in our study area (1-20 cm in TL) were estimated to be 4-18 months-old (Powles and Kohler, 1970, Bowering, 1976, Wenner, 1983, Burnett et al., 1992, Saborido-Rey et al., 2004, Hoff et al., 2000, Brassard et al., 2017. Further, based on the life histories of the four taxa, we know that juveniles settle on the seafloor between fall and winter (Bigelow and Schroeder, 1953, Kelly and Barker, 1961, Middleton and Musick, 1986. These results suggest that juvenile migration and settlement in benthic habitats in the MPA occur before July (or after September), and thus that seasonality is unlikely to explain differences in size between September and July, which supports signs of fish interannual growth. ...
... All four fish taxa were described as sedentary taxa in other studies (Bigelow and Schroeder, 1953, Sedberry and Musick, 1978, Wenner, 1983, Middleton and Musick, 1986, Scott, 1988, showing limited movements after settlement, mostly consisting in daily migrations between feeding and resting areas (Holmlund and Hammer, 1999). Considering that juveniles have a low mobility compared to adults, their movements are even more limited in time and space. ...
... Additionally, considering their migration patterns and poor swimming abilities, it is unlikely that juveniles (between 'Small' and 'Large' juveniles) undergo ontogenetic habitat shifts (Bigelow and Schroeder, 1953, Sedberry and Musick, 1978, Middleton and Musick, 1986, Scott, 1988). Had we not looked at fish distribution patterns across habitats per year, we probably would not have seen any influence of habitats on fish growth, and would have interpreted results as 'Small' and 'Large' juveniles distributed in different benthic micro-habitats. ...
Many fish species undergo ontogenetic habitat shifts as they grow to fulfill new biological, ecological and
environmental requirements. While relationships between fishes and large hard-substrate cold-water corals
(CWC) (e.g., Desmophyllum pertusum reefs) have frequently been studied, there are relatively fewer studies
examining the relationships of fish with habitats specifically provided by smaller corals (e.g., sea pens) in softbottom environments. Despite this knowledge gap around soft-bottom corals, growing evidence of their
importance has nonetheless justified their inclusion as conservation targets in numerous Marine Protected Areas
(MPA), including the Canadian Laurentian Channel MPA. Here, we performed ROV and near-seabed drift-camera
system surveys within the Laurentian Channel MPA in 2017 and 2018 to assess the influence of fish body size and
habitat type on fish small-scale distribution in a low-relief deep-sea soft-sediment environment. We compared the
local size structure of the four most abundant deep-sea demersal fish taxa of the channel (Redfish (Sebastes spp.),
Witch Flounder (Glyptocephalus cynoglossus), Marlin-Spike Grenadier (Nezumia bairdii) and Longfin Hake (Phycis
chesteri)) across one barren and five structural benthic habitats defined by the presence of nine dominant epibenthic invertebrates (actiniarians and CWCs). We used generalized additive models to identify biotic (benthic
habitats) and abiotic (depth, bottom types) covariates of size for each taxon. We observed 15,381 fish within the
43.6-ha study area, of which 7,511 fish were measured. Juveniles represented 99% of all fish measured, with a
notable increase in average fish size in 2018. While we did not find any associations between benthic habitats
and fish life stages, the analysis revealed a significant increase in fish size within sea pen habitats for all four taxa.
Conversely, we found a taxon-specific influence of bottom type on fish size for all taxa. In addition, Redfish and
Longfin Hake size was positively correlated with depth. For deep-sea demersal fish taxa of the MPA, our results
suggest that 1) sea pens provide nursery habitat for early-life stages, 2) fish undergo ontogenetic shifts in microhabitat use and specialization, and 3) fish-habitat associations appear to be facultative rather than obligate.
Through the use of in-situ video data, this study provided evidence that small and large fish do not use the same
micro-habitats, and that sea pens contribute significantly to fish habitat despite providing less habitat heterogeneity than reef-forming scleractinians or large gorgonians. These results contribute to empirical understanding
of fish-habitat relationships at different fish life stages and may inform fisheries management, as well as
monitoring efforts in the MPA and other protected deep-sea environments.
... Scott and Crossman (1973) reported sea lamprey consumption was popular amongst European immigrants to North America. Local fisheries for migrant prespawning adults existed in the mainstem Connecticut and Merrimack rivers (Massachusetts), the Susquehanna River (Pennsylvania), and probably in many Atlantic coast rivers before mainstem dams were built in the 19th Century (Vladykov, 1949;Bigelow and Schroeder, 1953). Smith (1970) speculated that commercial fisheries for sea lamprey did not develop in Massachusetts because of the short time that migrant adults occurred at river mouths. ...
... Smith (1970) speculated that commercial fisheries for sea lamprey did not develop in Massachusetts because of the short time that migrant adults occurred at river mouths. Larvae rearing in the lower reaches of rivers have been harvested locally for fish bait, particularly in the Susquehanna River and other southern rivers (Bigelow and Schroeder, 1953). ...
... While a few New England rivers (e.g., Merrimack, Connecticut) might have supported lamprey fisheries of local importance during the early half of the 19th Century, catch records are missing (Goode, 1884;Bailey, 1938;Bigelow and Schroeder, 1953). These fisheries likely ceased during the 19th Century, as dam construction in most rivers limited access of adults to upstream spawning and larval rearing habitat and abundance of sea lamprey decreased (Bigelow and Schroeder, 1953). ...
Three anadromous lamprey species support important commercial fisheries in the northern hemisphere, sea lamprey in the Iberian Peninsula and France, European river lamprey in the Baltic Sea countries and Russia, and Arctic lamprey in Russia. Pacific lamprey, Caspian lamprey, Korean lamprey and pouched lamprey are harvested for subsistence and local commerce on the Pacific coast of North America, and in Russia, China and Oceania, respectively. Habitat loss caused by human activities in rivers have reduced lamprey populations and collapsed most commercial fisheries worldwide. Overfishing is a concern because traditional fishing gears (e.g., pots, fyke nets) target lampreys during their upstream migration, usually in physical bottlenecks, which can result in exceedingly high fishing mortality. The reduction in catches has inflated lamprey prices and encouraged illegal fishing in certain countries (e.g., Portugal, Russia). The success of management actions for lamprey fisheries could be at risk due to knowledge gaps that still exist regarding stock structure, estimates of stage-specific mortality, distribution at sea, preferred hosts, and climate change impacts to the distribution and availability of adequate hosts. There is an urgent need for good-quality data from reported commercial landings and also from monitoring studies regarding the efficacy of mitigation and restoration efforts (e.g., habitat restoration, fishing regulations, artificial rearing and stocking). Involving the general public and stakeholders in the management and conservation of lampreys through outreach actions is crucial to promote the protection of the ecological and cultural values of lampreys and the understanding of their vulnerability.
... The abundance of adult Atlantic salmon, Salmo salar Linnaeus, 1758, returning to rivers around the North Atlantic Ocean has been closely watched since humans began to exploit the resource (Dunfield 1985;Mills 1989). Historically, salmon populations were so abundant writers related that fish nearly overflowed onto the riverbanks (Bigelow and Schroeder 1953;Hindar et al. 2007;Nyberg-Kallio et al. 2020). On the other hand, there have always been periods of scarcity (Huntsman 1931a;George 1982). ...
... Prior to 1985 commercial fishing and angling were allowed in most jurisdictions. Commercial fishing was closed in the USA in 1948 because both the salmon population and commercial landings were at low levels (Bigelow and Schroeder 1953;Baum 1997), and Canada closed its commercial fishery in the Maritime Provinces in 1972 to assist stock recovery but reopened it in 1981 (O'Connell et al. 1992). In other jurisdictions in the North Atlantic, fishing continued as in the past (Mills 1989). ...
... Because of its desirability as food, illegal and unregulated exploitation of Atlantic salmon populations has been a long-standing problem both in freshwater and at sea. Poaching and overexploitation in rivers have been a serious problem throughout its range for centuries (Atkins 1887;Bigelow and Schroeder 1953;Netboy 1980;Shearer 1992). Illegal fishing practices and overexploitation in coastal seas is well known and has plagued most fisheries jurisdictions (Dunfield 1985;Mills 1989). ...
ABSTRACT Adult returns to many Atlantic salmon wild and hatchery stocks of the North Atlantic have declined or collapsed since 1985. Enhancement, commercial fishery closures, and angling restrictions have failed to halt the decline. Human impacts such as dams, pollution or marine overexploitation were responsible for some stock declines in the past, but adult returns to river and hatchery stocks with no obvious local impacts have also declined or collapsed since 1985. Multiple studies have postulated that the recent widespread occurrence of low adult returns may be caused by climate change, salmon farming, food availability at sea, or marine predators but these possibilities are unsupported by stocks that persist near historic levels, loss of stocks remote from farm sites, a diverse marine prey field, and scarcity of large offshore predators. The decline and collapse of stocks has common characteristics: 1) cyclic annual adult returns cease, 2) annual adult returns flatline, 3) adult mean size declines, and 4) stock collapses occurred earliest among watersheds distant from the North Atlantic Sub-polar Gyre (NASpG). Cyclic annual adult returns were common to all stocks in the past that were not impacted by anthropogenic changes to their natal streams. A flatline of adult abundance and reduction in adult mean size are common characteristics of many overexploited fish stocks and suggest illegal, unreported, and unregulated (IUU) fisheries exploitation at sea. Distance from the NASpG causing higher mortality of migrating post-smolts would increase the potential for collapse of these stocks from IUU exploitation. By-catch of post-smolts and adults in paired-trawl fisheries off Europe and intercept adult fisheries off Greenland, in the Gulf of St. Lawrence, and off Europe have been sources of marine mortality but seem unlikely to be the primary cause of the decline. Distribution in time and space of former, legal high-sea fisheries indicated fishers were well acquainted with the ocean migratory pattern of salmon and combined with lack of surveillance since 1985 outside Exclusive Economic Zones or in remote northern regions may mean high at-sea mortality occurs because of IUU fisheries. The problem of IUU ocean fisheries is acute, has collapsed numerous stocks of desired species worldwide, and is probably linked to the decline and impending collapse of the North Atlantic salmon population.
... Enchelyopus cimbrius (Linnaeus, 1766) Bigelow and Schroeder (1953): 234-238 (description); Cohen and Russo (1979): description; Demir et al. (1985); Cohen (1990): description; Deree (1999): feeding, age and growth; Lampart-Kałużnicka and Heese (2015): biology; Iwamoto and Cohen (2016): keys. ...
... The morphological description of E. cimbrius is mainly based on meristic characters (Bigelow and Schroeder 1953;Cohen and Russo 1979), as biometrics characters are poorly described. Exceptions are found in Demir et al. (1985) for post-larvae and juveniles and Svetovidov (1948) for adults. ...
A taxonomic characterisation of Enchelyopus cimbrius (Gadiformes, Gaidropsaridae) is presented on the basis of 11 specimens from the North Atlantic. Identification was carried out by integrative taxonomy, combining the examination of morphological and molecular characters. The former are consistent with previous descriptions, but new biometric and meristic data for the species are provided, showing ontogenetic changes with respect to post-larvae-pelagic juveniles. Length-weight relationships of 44 specimens showed isometric growth, while the length-length relationships of eight body parts of the species showed differential allometric growth. The molecular analysis resulted in the addition of 11 new sequences of cytochrome c oxidase subunit 1 (COI) to the molecular repositories. DNA barcoding supports the morphological identification of Enche-lyopus cimbrius specimens and confirms the amphi-Atlantic distribution of the species. Updating the taxonomic data can be useful to confirm the current status or to identify divergences and also to better characterise and delimit each species, contributing to a better understanding of intraspecific variability, both morphological and molecular.
... The Gulf of Maine is a marginal sea of the North Atlantic Ocean and is traditionally characterized as a distinct combination of temperate and subarctic conditions. The region has historically been associated with plentiful fisheries and economic opportunity, providing rich habitat for a variety of marine species, including those with commercial (e.g., American lobster Homarus americanus), recreational (e.g., striped bass Morone saxatilis), and ecological value (e.g., Calinus finmarchicus) (Bigelow and Schroeder, 1953;Fish, 1936). However, marine biomes around the world remain in a near-constant state of flux from anthropogenic activities (Wright and Kyhn, 2015), which can lead to physical, chemical, and biological changes. ...
... Recent surveys of pinniped abundance in Maine estimate the harbor seal population to have exceeded 61,000 as of 2018 (Sigourney et al., 2021), and pupping surveys have indicated a growing gray seals population in the region more broadly (Wood et al., 2020). Though white sharks have historically been documented in Maine waters Schroeder, 1936, Bigelow andSchroeder, 1953), fewer than 20 records of sightings, strandings, or fishery encounters were reported between 1880 and 2000 (Casey and Pratt, 1985;Mollomo, 1998;Curtis et al., 2014). However, there are signs that the WNA white shark population is recovering from historical overfishing (Curtis et al., 2014;Winton et al., 2023), and their presence in the region may be increasing. ...
While significant progress has been made to characterize life history patterns, movement ecology, and regional estimates of abundance of white sharks (Carcharodon carcharias) in the Western North Atlantic (WNA), patterns of spatial distribution remain relatively unknown in the northern Gulf of Maine. In this study, we utilize data collected from multiple acoustic telemetry projects from 2012-2023 to assess the spatiotemporal distribution of white sharks along sections of the Maine coastline and regional offshore waters. Acoustic receivers were deployed each year from 2012-2019 (mean number of receivers ± SD: 11 ± 4), and effort increased following the first-ever white shark related fatality in Maine in 2020 (2020-2023: 40 ± 15). In total, 107 white sharks tagged by researchers in the WNA were detected, with the majority (n = 90) detected in shallow (<50 m depth) waters post-2019. Reflective of the tagged population at-large, total length of individuals ranged from 2.1 to 4.9 m, with most individuals estimated to be in the juvenile or subadult life stages. White sharks were detected between the months of May-December, with peaks between July and September, and were observed in close proximity to several of Maine’s western beaches and islands/outcroppings, with higher numbers observed at several sites in eastern Casco Bay. Although the overall quantity of detections was relatively low when compared to white shark aggregation sites in other regions, this study provides baseline information on the presence of this species in the northern Gulf of Maine. While future research should include expanded receiver coverage in eastern Maine and the use of additional tagging technologies, this study contributes early insights for informing marine spatial planning, fisheries management, and conservation strategies for white sharks in the region.
... Striped bass are known to occur along the eastern coast of Nova Scotia, north to Cape Breton Island coastal waters (Fig 1;Bigelow & Schroeder 1953, Scott & Scott 1988, and its inland sea, Bras d'Or Lake (Cash et al. 1985). Cape Breton straddles two management zones (Designatable Units -DUs) in which striped bass were assessed as threatened and/or endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2012) but are unlisted in this region by the Canadian Species at Risk Act (SARA). ...
... Thus, departure events for < 24-hour periods are not resolvable by our methods. Given the lack of detections from other nearby receiver arrays striped bass that left the MRe probably remained in the relatively local area of Mira Bay (Bigelow & Schroeder 1953). ...
The occurrence of striped bass outside the immediate vicinity of known spawning rivers in Canada is neither widely understood nor well studied. Striped bass in Canada are managed and assessed within three distinct units, the Bay of Fundy, the Gulf of St. Lawrence, and the St. Lawrence River; but stocks that may occur outside these units are unrecognized. We document a previously unstudied aggregation of striped bass in the Mira River estuary (MRe), Cape Breton Island (46° 01′N, 60° 03′W), a location on the east coast of Nova Scotia omitted from present management units but which has been long reported to host an aggregation. From July 2012 to November 2014, 62 striped bass within MRe were sampled and 31 were surgically implanted with VEMCO acoustic transmitters. Striped bass ranged in size from 31.6 to 125.0 cm total length and age 3 to 24 years. Acoustic telemetry from 2012 to 2015 elucidated residency and fidelity to the MRe with mid-estuary overwintering every year, freshwater residency of the adult population during spring, and a summer through autumn aggregation in the lower estuary. Of the 31 acoustically tagged striped bass, 24 remained in MRe throughout the study, six exhibited mid-summer departures to the Atlantic Ocean but returned by mid-autumn, while one left the MRe and was never detected again. Mira River SB with acoustic tags were never detected at nearby Ocean Tracking Network telemetry infrastructure. Striped bass stocks exhibit similar residency and fidelity patterns to their natal rivers and estuaries elsewhere in its Atlantic coast range which suggests the Mira River aggregation constitutes a possible distinct stock yet unrecognized by Canadian fisheries managers.
... Bigelow and Welsh (1925). Bigelow and Schroeder (1953), Martin and Drewry (1978), and Fahay (1983) give information on eggs and larvae of western Atlantic pleuronectine flatfishes. The most comprehensive work dealing with early life history stages of flatfishes from the western North Pacific is Pertseva-Ostroumova (1961). ...
... Russell, 1976 Ehrenbaum, 1905-1909 Dando, 1975 Russell, 1976 Agassiz, 1882 Agassiz and Whitman, 1885 Brook, 1890 Ehrenbaum and Strodtman, 1904 Ehrenbaum, 1905-1909Dannevig, 1919Colton and Marak, 1969 Roule and Angel, 1930 D'Ancona, 1933aVodyanitsky and Kazanova, 1954 Fives. 1970b Schmidt, 1905a, 1906a Ehrenbaum, 1905-1909 Russell, 1976 Bini, 1971 Dekhnik, Brownell, 1979 Demir, 1982Markle, 1982 Facciola, 1882 Emery, 1886 Manon, 1894b D' Ancona, 1933a Russell, 1976 Heincke and Ehrenbaum, 1900 Schmidt, 1907b Ehrenbaum, 1905-1909 Kennedy and Fitzmaurice, 1969 Russell, 1976 Aggassiz, 1882 Aggassiz and Whitman, 1885 Hildebrand and Cable, 1938Bigelow and Schroeder, 1953Miller and Marak, 1959Barans and Barans, 1972Serebryakov, 1978 Zvyagina, 1961 Schmidt, 1905a, 1906a Rass, 1949 Kuz-min-Karovaev, 1930Khaldinova, 1936Ponomareva, 1949 Rass, 1949 Mukhacheva, Aronovich et al., 1975 Dunn and Vinter, 1984 Schmidt, 1906a Roule and Angel, 1930Heincke and Ehrenbaum, 1900 Masterman, 1901 Schmidt, 1905a, 1906aDannevig, 1919 Nakahara, 1962 Johnson, 1978 Hildebrand and Cable. 1938 Fahay. ...
... The spawning seasonality we observed is similar to earlier studies in the region and elsewhere. Bigelow and Schroeder (1953) reported Cusk in the Gulf of Maine spawning in spring and early summer, commonly into July. Cusk eggs in the Gulf of Maine and Georges Bank were collected from March until November, with peak egg abundance in May and June (Berrien and Sibunka 1999). ...
... The lower reproductive investment by males could make more energy available for growth or spawning behavior (guarding females or breeding site) or enable spawning over a more protracted spawning season. Significant migration and movement has been suggested as unlikely for Cusk in multiple regions (Bigelow and Schroeder 1953;Johansen and Naevdal 1995;Knutsen et al. 2009); however, their seasonal movements are not well known, without any known tagging studies on the species to date. The low GSI of males and limited seasonal change in gonad size and appearance complicate macroscopic classification. ...
Cusk Brosme brosme are fished across the northern Atlantic Ocean, but even basic biological data are limited in part by their difficult‐to‐sample deep and structured habitats. We sampled fish from a variety of sources across the Gulf of Maine to provide comprehensive life history information (age and size at maturity, fecundity, sex ratio, growth) for this data‐poor species considered by National Oceanic and Atmospheric Administration Fisheries as a species of concern. Gonad histology and gonadosomatic index data indicated peak spawning in late spring (May–June), with limited spawning activity into summer. The histologically derived length at 50% maturity for female Cusk was 39.5 cm TL. Fecundity varied from a quarter million to four million oocytes, with a positive allometry versus size indicating that larger females have proportionally higher fecundity than smaller females. Male Cusk had unusually low gonadal investment for a gadiform, and males of all sizes examined (down to 21 cm) had spermatozoa present. Male maturity was equivocal even when the relative proportions of sperm stages were quantified through image analysis of gonad histology; further anatomical and physiological studies of small males are required to assess functional maturity in male cusk. The sex ratio at length indicated more males at larger sizes, and males had faster growth and larger size at age than females. Condition patterns also suggested lower condition for females than males after spawning and generally less variable condition for males. Gonadal investment, relative condition, and growth patterns all suggest differences in energy allocation between the sexes. This data‐poor species has an uncertain stock status in U.S. waters; therefore, the results of the current work provide important information to its management.
... In the early half of the 1800s, they were abundant inshore throughout Massachusetts Bay, but were soon fished out once a commercial fishery was established. The fishery then shifted offshore, and by 1850, stocks had been severely depleted on Georges Bank (Bigelow and Schroeder 1953). American harvesters, at that time, were allowed access to Canadian waters (Lear 1998) and moved sequentially northward into Canada, focusing first on southern areas but then fishing as far north as the Canadian Arctic in 1866 (Trumble 1993;Grasso 2008). ...
... Observations of spawning Atlantic halibut on the eastern Scotian Shelf and in the eastern Gulf of Maine have been inferred or observed from April to early September spawning from Georges Bank to the Grand Banks, with some geographic variation (late spring off Greenland; summer off the U.S., and in September on the Scotian Shelf ) at depths of 300-400 m. These spawning depths are shallower than has been observed off Europe (Bigelow and Schroeder 1953). ...
Interactions between spatial dynamics and stock structure in marine fishes have largely focused on stocks in decline; stock structure is rarely re-visited for expanding species. Here, the spatial ecology of Atlantic halibut (Hippoglossus hippoglossus L.), managed as four stocks in the Northwest Atlantic, is reviewed. Halibut collapsed under high exploitation in the mid-19th century, but the Canadian fisheries value has increased seven-fold since the early 2000s. Atlantic halibut's thermal habitat has increased due to warming, possibly contributing to its expansion. Genomic evidence differentiates two populations in the four management units, whereas there is non-genetic spatial structure within each of the stock boundaries. There are different core juvenile areas and a diversity of spawning migration patterns influenced by timing, fish size, maturity state, and distance between summer-feeding and over-wintering habitats. From tagging studies, multiple estimates of median distance at recapture (∼3-90 km) are much less than the spatial domain of each stock. Growth rates are faster in the warmer south, as predicted by growing degree day. The current perspective of Atlantic halibut spatial structure is that there are two distinct populations, and within each, there are subpopulations composed of multiple migratory contingents. The level of mixing on common spawning grounds both among and within subpopulations is only partly understood.
... This behaviour may occur more readily in cooler waters associated with the SS and off Newfoundland compared to more temperate waters (Murawski and Finn 1988). Optimal water temperatures for adult Haddock range from 4-7 ˚C, with all life history stages of Haddock typically avoiding waters with temperatures above 10 ˚C (Bigelow andSchroeder 1953, Cargnelli et al. 1999). ...
... However, more recent surveys indicate that they do not currently occur in the southern range south of North Carolina (Rulifson 1982;Rulifson et al. 1994). Blueback herring range from the St. Johns River, Florida (Hildebrand 1963;Williams et al. 1975) to the Miramichi River, New Brunswick (Bigelow and Schroeder 1953;Leim and Scott 1966). Although alewife and blueback herring co-occur throughout much of their respective ranges, alewife are typically more abundant than blueback herring in the northern portion of their range (Schmidt et al. 2003). ...
The Massachusetts Division of Marine Fisheries (DMF) is the agency responsible to monitor and manage diadromous fish
populations in the coastal waters of Massachusetts. Included in this role is participation with the Atlantic States Marine
Fisheries Commission (ASMFC), the interstate fisheries management authority that coordinates the management of
marine species that migrate across state boundaries. Annual compliance reports are provided to the ASMFC on DMF’s
management and monitoring activities with river herring and American Shad. This technical report reports on the status
of American shad and river herring management and monitoring by DMF for 2019 and is based on the ASMFC annual
report (Sheppard et al. 2020) with more details on monitoring and restoration activities to provide this information to
a wider public audience. A highlight of 2019 was increased sizes of river herring spawning runs in most coastal regions
of Massachusetts. Unexpectedly, given the significant drought of 2016, increased spawning runs lead to the highest
counts seen among monitored rivers since the river herring harvest ban in 2005. For the first time in this period, four
rivers exceeded a half million fish (Mystic River, Monument River, Herring River, Harwich, and the Nemasket River). The
Stony Brook in Brewster and Herring Brook in Pembroke set time series highs with over 400,000 fish. The Herring River
run in Harwich was the first monitored run since the Nemasket River in 2002 to exceed a million fish.
... (Yoshida, 1980). Main species reported in western Atlantic are: clupeids, Peprilus paru, Leiosomus xanthurus, Anchoa sp, Scomberomorus sp., Prionotus sp., Loligo sp., Penaeus sp. and squid (Bigelow and Schroeder, 1953;Boschung, 1966). Atlantic bonito searches for its food early in the morning and evening, generally in the coastal zone (Postel, 1954).The species predators are Acanthocybium solandri, Coryphaena hippurus and Sarda sarda. ...
... A. radiata exhibits signicant spatial variation in physical characteristics, spatial differences that have led to confusion in its taxonomy. Based largely on variation in size, A. radiata was once regarded as two species, one in the Northwest Atlantic, the other in the Northeast Atlantic [45] until they were merged in 1953 [46]. ...
We examine the distribution, habitat association, morphometrics, meristics, and reproductive attributes of Amblyraja radiata over much of its Canadian range, Grand Banks to Arctic waters. It is distributed widely on the shelf and upper slope between 30 and 1288 m, reaching highest density in 100–400 m and occupying most available temperatures, between −1.0 and 8.8 °C, but concentrating in 1.6–3.5 °C. The maximum (and average) size decreases with increasing latitude in a continuum from 102 cm (55 cm) in the south, to 45 cm (20 cm) in the north. The proportion of mature fish increases with depth (40% at 0–50 m to 80% at 1150–1200 m) and temperature (35% at <0 °C to 55% at 5+ °C). The size at maturity decreases south to north; size at onset of maturity in males—43 (south) to 19 (north) cm, in females—49 to 23 cm; length at 50% maturity in males—74 to 44 cm, in females—66 to 40 cm. A. radiata maturity is also reflected in the rapid increase in the size of secondary sexual characteristics. Some meristics were consistent over the entire study area (spines near the spiracles and shoulders) while others varied with latitude (teeth rows, midline spines, spines near the eyes, % dorsal fins joined, spines between dorsal fins) or by fish length/maturity; the tail length/total length as a proportion of total length decreased during Stage 1 then increased at onset of maturity.
... Recently, a study carried out a molecular review of the genus Gymnura van Hasselt, 1823, which was used to reconstruct the evolutionary history of the Gymnuridae family (Gales et al., 2024). According to the work, the lineage of Gymnura altavela present in the southeast and south of Brazil had already been classified as Gymnura hirundo (Lowe, 1843) from individuals collected in this region (Ribeiro, 1907;Bigelow and Schroeder, 1953) and later synonymized as G. altavela. However, the type specimen of G. hirundo comes from the island of Madeira in the eastern Atlantic. ...
Little is known about the Chondrichthyes fauna of the state of Espírito Santo, southeastern Brazil, notably on the species composition, distribution, and biology. Historically, only a few studies have focused on these issues. Basic taxonomy is one of the main tools employed in cataloguing, organizing, and initiating other, more specific, assessments regarding regional diversity. In this context, this study presents the most comprehensive list of shark and ray species occurring in the state of Espírito Santo to date. The compiled data were obtained from specimens deposited in ichthyological collections, literature reviews, and samplings conducted at fisheries landings and onboard commercial fleet vessels. The findings indicate 79 species, comprising 51 sharks and 28 rays. A total of 53.2% of threatened Brazilian marine elasmobranch species occur in the area, indicating the importance of carrying out local studies focusing on this group. A first record for the Brazilian large-eyed stingray, Hypanus marianae , was also observed for the state, increasing the southern limit of the species known distribution, previously considered restricted to the North and Northeast coasts.
... Southern stingrays are common in coastal waters, along the Western Atlantic, ranging from New Jersey, USA to Brazil including the shallow tropical waters of the United States Virgin Islands (USVI) (Bigelow and Schroeder, 1953;Carlson et al., 2020). Adult southern stingrays and their congeners (e.g. ...
This study provides some of the first evidence of how a common Caribbean fish species that relies on seagrass and sand habitats interacts with an invasive seagrass. The invasive seagrass Halophila stipulacea, first documented in the Caribbean in 2002, has rapidly expanded its range, displacing native seagrasses, and overgrowing bare sand. The southern stingray (Hypanus americanus) uses shallow seagrass and sand habitats for foraging. This paper examined the impacts of the invasive seagrass, H. stipulacea, on southern stingray behavior, foraging and movement patterns using acoustic telemetry and visual observations. From 2015 to 2018, 15 southern stingrays (14 juveniles of unknown sex and 1 female) were tagged with acoustic transmitters and passively monitored within an acoustic array in Brewers and Perseverance Bays, St. Thomas, United States Virgin Islands. The residence time, rates of movement and activity spaces for 50% and 95% utilization distributions (UD) were calculated for day and night periods. Tagged southern stingrays were detected within the array on average for 260 d (range 11–801 d) and residency for all individuals averaged 53% over the monitoring period (1079 d). Mean rates of movement per individual ranged from 40 to 150 m h−1, was lowest during the nighttime and were significantly higher during crepuscular periods. Activity spaces during day and night periods were nearly identical and averaged 0.05 km2 and 0.25 km2 for 50% and 95% UD, respectively. Distances between day and night 50% UD activity spaces was 148 m (range 8–409 m) and mean percent overlap was 38%. In addition to acoustic monitoring, benthic cover of available habitats and visual surveys of stingray behavior and habitat preferences were conducted along fixed transects. Monotypic stands of the invasive H. stipulacea seagrass represented 42% of benthic cover, followed by bare sand (27%), mixed patches of native and invasive seagrasses (23%) and the native Syringodium filiforme (7%). A habitat selection index (HSI) comparing the percent cover of available habitats and habitats occupied by stingrays found a strong preference for the native seagrass S. filiforme (HSI = 2.30) and bare sand (HSI = 1.79) compared to H. stipulacea (HSI = 0.70). Visual surveys also revealed that 50% of foraging stingrays were in S. filiforme, while 28% and 17% were foraging in H. stipulacea and bare sand, respectively. Our results are an important baseline for examining how further expansion of H. stipulacea may affect southern stingray movement patterns and foraging preferences.
... Cownose rays (family Rhinopteridae) are highly migratory pelagic stingrays that occur worldwide in tropical and temperate seas (14,15). Currently, eight species have been identified in the sole genus Rhinoptera, including three in the North Atlantic basin-R. ...
Cownose rays (Family Rhinopteridae) are highly migratory pelagic rays that are generally restricted to continental shelves. Despite 100's of years of natural history records, cownose rays have never been reported in Bermuda, an atoll-like coral reef ecosystem that is separated from the continental mainland United States by ~1,000 km. Here we compile evidence that the Atlantic cownose ray ( Rhinoptera bonasus ) has recently established in Bermuda, supported by both morphological and genetic data. Potential ecological and inter-specific competition concerns are presented as well as probable physical mechanisms that facilitated this recent and presumed range expansion.
... Most studies on smelt and Blueback Herring have concentrated on the adult stage. Some life history information has been published already for both species (Langlois 1935;Bigelow and Schroeder 1953;McKenzie 1964;Leim and Scott 1966;Scott and Crossman 1973;Messieh 1977). Few studies, however, have been undertaken on the egg or larval stages. ...
... The diameter of samples of eggs taken from several bays are much smaller than those previously reported from Canadian waters (2.5 to 3.1mm, Cox and Anderson 1922). The eggs are also smaller than those measured from other localities (2.2 to 2.6 mm in the USA (Bigelow and Schroeder 1953), 2.25 to 2.5mm in Scotland (McIntosh and Masterman 1897), 2.3 to 2.5 mm in Greenland (Jensen 1944), 2.4 to 2.7 mm in White Sea (Andriyashev 1954)). < The hatching period of 21 to 54 days falls within the range of 14 to 70 days quoted for other parts of the world (Cox and Anderson 1922). ...
... The specimen was taken in a weir at Halls Harbour (Bay of Fundy), Kings County, Nova Scotia. This is 350 miles north of the range limit of Massachusetts Bay given by Bigelow and Schroeder (1953). It was captured sometime during July or August 1947, and a mount prepared by Bleakney measured 3914 inches (99.6 cm). ...
... The wide diversity of food items consumed was unexpected since bluebacks have previously been reported to be primarily planktivorous (Bigelow and Schroeder 1958;Hildebrand 1968), The limited 1981 data suggest that prey other than zooplankters are consumed infrequently if sufficient zooplankters (or large zooplankters such as Daphnia) are present. However bluebacks are also capable, as the 1980 data. demonstrate, of foraging opportunistically on other riverine fauna and terrestrial insects, which could also explain Frankensteen's (1976) unusual finding that chironomids were the dominant prey of blueback herring in the Tar River. ...
This article investigates whether blueback herring fed in freshwater during their spawning migrations. They did consume freshwater zooplankton and even drifting benthic insects.
... The newly available Field Guide was abridged and slightly modified from the recently published Fishes of the Salish Sea: Puget Sound and the Straits of Georgia and Juan de Fuca (2019), a universally acclaimed instant classic (e.g., Quinn 2020; Sidlauskas 2020; Bodensteiner 2021) that stands proudly on my bookshelf next to other heralded regional ichthyological works such as Fishes of the Gulf of Maine (Bigelow and Schroeder 1953) and The Sea Fishes of Southern Africa (Smith 1949). The Field Guide reduces the hefty three-volume hardcopy set to a manageable size without losing any of the documented fish species. ...
... Uncertainties remain about how all underutilized species may respond to climate change through distribution changes, physiological effects, and indirect effects that affect populations across community and ecosystem scales Henderson et al., 2017;NEFSC, 2017). For example, butterfish have ecological importance as a prey species for both small and large commercial fish (Bigelow and Schroeder, 1953;Cross et al., 1999). Emerging species moving into northern areas from the mid-Atlantic due to warming waters (e.g., silver hake) (Nye et al., 2009) have the potential to increase predatory demand on butterfish therefore influencing their overall resilience to changing conditions. ...
Developing and diversifying market opportunities for lesser known yet abundant seafood species has been a successful strategy for seafood businesses in the Northeast United States. Since climate change and other stressors are currently threatening the economic vitality of New England’s seafood industry, it is important to identify if there are lesser-known species that could simultaneously support additional market opportunities and remain resilient in a warming climate. We developed a quantitative definition for the term “underutilized species’’ based on five criteria derived from science-based sustainable fishing metrics. Using this definition, we evaluated 47 stocks in the Northeast United States during the initial time period of 2013-2017 to identify seven underutilized finfish species that could be considered for new market opportunities as part of a climate-smart approach: 1) Acadian redfish (Sebastes fasciatus), 2) Atlantic pollock (Pollachius virens), 3) butterfish (Peprilus triacanthus), 4) haddock (Melanogrammus aeglefinus), 5) scup (Stenotomus chrysops), 6) silver hake (Merluccius bilinearis), and 7) white hake (Urophycis tenuis). The climate resiliency of these resulting seven species was then evaluated using a framework consisting of species-specific metrics on climate sensitivity, directionality (of responses to climate impacts) and future habitat availability under warming scenarios. Our results show that assessing underutilized species on a regular basis and evaluating their ongoing responses to climate change can be a part of a climate-smart approach towards building more diversified and adaptive markets.
... To evaluate the effects of salinity fluctuations on coastal species, we have focused on the Gulf killifish, F. grandis. The Gulf killifish is characterized by a wide geographic range, inhabiting coastal marshes across the northern Gulf of Mexico (GOM) and Cuba at varying salinities (Bigelow and Schroeder 1953;Lee et al. 1980;Robins et al. 1986;Scott and Crossman 1998). A previous study showed nine different Cyprinodontoid species from urban and vegetated creeks in the Wolf-Perdido Bay drainage and found that the Gulf killifish was the most abundant in creeks draining urbanized watersheds (Wedge and Anderson 2017). ...
Environmental conditions are one of the main factors influencing the distribution of species across ecosystems. As humans modify both abiotic and biotic parameters across different ecosystems, it is essential to understand how anthropogenic activities can affect the distribution of species and/ or populations. Changes to coastal ecosystems via urbanization can lead to rapid fluctuations in salinity of coastal areas due to the increased runoff of freshwater during storms. These fluctuations in salinity are known to promote shifts in the community structure and abundance of coastal fishes, yet questions remain on their role in shaping the genetic divergence of persistent populations. In this study, salinity of coastal watersheds was monitored in four different sites of the Pensacola Bay and Wolf-Perdido Bay drainage. Salinity records showed increasing salinity variability between sites with low, intermediate, and high urbanization. On each of these sites, differences in the mitochondrial markers cytochrome oxidase 1 (CO1) and control region (CR) were evaluated for the Gulf killifish, Fundulus grandis. The genetic results indicate the largest genetic differences were found among individuals at sites with intermediate and high urbanization, and among individuals at distant sites with intermediate and low urbanization, for CR. These results suggest that both geographic distance and differences in salinity regimes have the potential to promote genetic structure among killifish populations. Overall, the results from this study indicate that urbanization can have significant effects on the salinity regimes of the northern Gulf of Mexico, while highlighting the potential effects urbanization and geographic distance can have on genetic composition of coastal fishes.
... Referências - Bane, 1965; Barros & Paiva, 1965;Bigelow & Schroeder, 1953;Collette, 1978;Oelschlãger, 1977;Palmer & Oelschlager, 1976; ...
... In the western Atlantic Ocean, Atlantic Wolffish ranges from Greenland and Labrador to the Gulf of Maine, where it has historically been part of groundfish fisheries (Bigelow and Schroeder 1953;Albikovskaya 1982;Riget and Messtorff 1988). In our study area, the Gulf of Maine, Atlantic Wolffish are distributed from 20 to 300 m, along the northern flank of Georges Bank, and in both U.S. and Canadian waters, representing the southern extent of this species' range ( Figure 1; Nelson and Ross 1992;Briggs and Waldman 2002;Rountree 2002). ...
Stock assessments of U.S. Atlantic Wolffish Anarhichas lupus are hampered by a landings moratorium and low catches in fishery‐independent surveys. Working with the commercial fishing industry, we collected hundreds of fish to overcome a lack of regionally specific life history information. Based on ages from sectioned otoliths, Atlantic Wolffish are long lived (maximum observed age: males = 31 years, females = 29 years). A Gompertz growth model showed that Atlantic Wolffish exhibit dimorphic growth—with larger males across all ages on average. Preliminary estimates of total mortality ranged from 0.15 to 0.21 and were lower than an estimate measured at the beginning of the moratorium. Based on gonad histology, a cohort of vitellogenic oocytes emerged in mature females by April and developed group synchronously to ovulate primarily in October. Skip spawning, which accounts for nonannual spawning, was observed in 5.6% of the mature females. Accounting for abortive maturation, a physiological event that delays functional maturation, improved precision and reduced bias of maturity estimates. The resulting median length at functional maturity was 53 cm total length (95% confidence interval = 49–56 cm), and the median age was 6.7 years old (6.2–7.2 years). These estimates are smaller and younger than elsewhere in the western North Atlantic Ocean, confirming that regionally specific maturity parameters are relevant when assessing reference points of the U.S. Atlantic Wolffish fishery.
... The benthic-feeding wrymouth is the only species in the Cryptacanthodidae family to reside in the northwest Atlantic, where it ranges from southern Labrador to New Jersey (Bigelow & Schroeder, 1953). Other members of the family are found in the north Pacific Hikita & Hikita, 1950). ...
Predation by infaunal and epibenthic predators is often an important determinant of marine soft‐bottom community structure. The role of the predatory, benthic‐dwelling fish, the wrymouth (Cryptacanthodes maculatus), in the soft‐bottom food web has received little attention. The purpose of our study was to examine spatial and temporal variability in diet and trophic position of wrymouth at two lower intertidal sites in eastern Maine, USA. Wrymouth, their potential prey, and primary producers were collected in the spring and summer of 2013 in Machiasport and Beals, Maine. Stable isotope analysis was used to determine trophic position of the fish and its potential diet. Wrymouth δ13C signatures were influenced by location and ranged from −12.6‰ to −11.5‰, whereas δ15N signatures varied little (12.3‰–12.7‰) between locations or seasons. Wrymouth trophic position ranged from 3.02 to 3.48, indicating that they are tertiary consumers. The intertidal zone consisted of two distinct clusters of taxa, characterized by the presence of either macroalgae (mostly fucoids) or eelgrass (Zostera marina). Wrymouth diet consisted primarily of predatory polychaetes. Stable carbon and nitrogen isotope signatures varied across seasons and locations for multiple species, including our base species, Mya arenaria. Results suggest wrymouth are generalist feeders with limited seasonal and spatial variation in diet. Bottom‐up processes, however, are fundamentally different between the two study sites and influence their trophic structure. This result highlights the importance of collecting baseline data and evaluating trophic interactions at multiple spatial scales within small regional areas in coastal systems.
... Such currents promote the movement of recruits and juveniles of H. antarctica across the Southern Hemisphere, in part due to their pelagic behavior. H. antarctica juveniles are known to associate with surface waters, and are often associated with flotsam, which likely provide shelter and food (Bigelow and Schroeder, 1953;Leim and Scott, 1966;Haedrich, 1967;Horn, 1970;Horn and Massey, 1989;Last et al., 1993;Duffy et al., 2000). Although still little understood, the use of drift algae for shelter by juvenile H. antarctica may potentially structure individual movement, and therefore contemporary population connectivity. ...
Working Towards a Blue Future: Promoting Sustainability, Environmental Protection and Marine Management: Examples from the UK Government Blue Belt Programme and Current International Initiatives
... Uniquely, herring from the BOF and Gulf of Maine region have an advantage in that there is a unique second annual phytoplankton bloom that occurs between September and December (27). These blooms are accompanied by increases in krill, another food source for herring (2). Supporting this is the finding of increased biomass of sub-adult herring present in St. Mary's Bay during this period in 2016, along with the rare presence of feeding humpback whales there in November and December (1). ...
Atlantic herring from a fish kill that stranded in 2016 in St. Mary's Bay Nova Scotia, Canada were sub-adult, and had reduced body condition compared to reference herring. Some exhibited spine abnormalities , had elevated cadmium, with significant numbers exhibiting otic (ear) capsule bleeds. Morphometrics from fish kill herring (n=90) were compared to age region-matched reference herring. Major findings include 62% reduced slope of length weight relationship and lower weight for age compared to the reference herring group. Fish kill herring had elevated liver cadmium (0.20 µg/g ± 0.08), magnesium (549.1 µg/g ± 157.9) and zinc (31.6 µg/g ± 3.5) as well as muscle magnesium (567.5 µg/g ± 176.7) and zinc (7.68 µg/g ± 2.9). Additional findings include a 10% incidence of spine curvatures, while 65% had otic capsular bleeds. Implications include possible underlying health issues from environmental stressors, including elevations in cadmium, reduced body size profiles and spine defects , together with potential exposure to dramatic pressure changes within the confines of St. Mary's Bay (eg. otic bleeds in some herring) could have contributed to their eventual stranding. [JMATE 2019;11(2):18-28]
... Puisque l'alose savoureuse est anadrome, elle fréquente les habitats marins et ceux d'eau douce au cours de son cycle de vie. Son aire de répartition naturelle s'étend sur une importante portion de la côte atlantique (figure 2), du fleuve Saint Johns, dans le nord de la Floride, jusqu'au fleuve Saint-Laurent (Leim, 1924;Bigelow et Schroeder, 1953;Leim et Scott, 1966;Scott et Crossman, 1974;Scott et Scott, 1988). ...
... Such currents promote the movement of recruits and juveniles of H. antarctica across the Southern Hemisphere, in part due to their pelagic behavior. H. antarctica juveniles are known to associate with surface waters, and are often associated with flotsam, which likely provide shelter and food (Bigelow and Schroeder, 1953;Leim and Scott, 1966;Haedrich, 1967;Horn, 1970;Horn and Massey, 1989;Last et al., 1993;Duffy et al., 2000). Although still little understood, the use of drift algae for shelter by juvenile H. antarctica may potentially structure individual movement, and therefore contemporary population connectivity. ...
Quantifying the level of population connectivity within and between geographically separated single-species deep-water fisheries stocks will be vital for designing effective management plans to preserve such populations. Despite this, stock structure in many fisheries is still poorly described and, at best, subject to precautionary management. Here we use rapidly evolving mitochondrial genes and microsatellite markers to investigate population connectivity patterns in commercially targeted Hyperoglyphe antarctica populations between four seamounts within the Tristan da Cunha Exclusive Economic Zone (EEZ). We find little evidence of population genetic structure between fished populations, with both mtDNA and microsatellite markers showing that there is low genetic population diversity (reflecting substantial gene flow) across the four seamounts. We also find little genetic differentiation between H. antarctica across the wider Southern Hemisphere. Such results support the role for coordinated management of all four populations across the seamounts, and potentially including stocks associated with Australia and New Zealand, with expansion of the fishery clearly having the potential to substantially impact the source of recruits and therefore wider population sustainability.
... and surface-to-bottom temperature differences reach approximately 10°C (Lentz, 2017). From July to October, rapid warming of the Cold Pool occurs over Georges Bank, and more gradual warming occurs in central and southern MAB (Bigelow & Schroeder, 1953;Houghton et al., 1982;Lentz, 2017) due to heat fluxes across its surface and lateral boundaries (Benway & Jossi, 1998;Chen, 2018;Lentz, 2017). Near the 60-m isobath, maximum bottom temperatures are not reached until mid-November; however, warming is faster in shallower water due to a vertical turbulent heat flux from the thermocline to the Cold Pool (Lentz, 2017). ...
The U.S. East Coast has 1.7 million acres of federal bottom under lease for the development of wind energy installations, with plans for more than 1,500 foundations to be placed. The scale of these wind farms has the potential to alter the unique and delicate oceanographic conditions along the expansive Atlantic continental shelf, a region characterized by a strong seasonal thermocline that overlies cold bottom water, known as the “Cold Pool.” Strong seasonal stratification traps cold (typically less than 10°C) water above the ocean bottom sustaining a boreal fauna that represents vast fisheries, including the most lucrative shellfish fisheries in the United States. This paper reviews the existing literature and research pertaining to the ways in which offshore wind farms may alter processes that establish, maintain, and degrade stratification associated with the Cold Pool through vertical mixing in this seasonally dynamic system. Changes in stratification could have important consequences in Cold Pool setup and degradation, processes fundamental to high fishery productivity of the region. The potential for these multiple wind energy arrays to alter oceanographic processes and the biological systems that rely on them is possible; however, a great deal of uncertainty remains about the nature and scale of these interactions. Research should be prioritized that identifies stratification thresholds of influence, below which turbines and wind farm arrays may alter oceanographic processes. These should be examined within context of spatial and seasonal dynamics of the Cold Pool and offshore wind lease areas to identify potential areas of further study.
... During the course of evolution, mobulid rays have moved from a benthic to a pelagic lifestyle, where they perform pectoral fin movements similar to the flapping movement of birds' wings, while their enlarged pectoral fins also allow them to propel their bodies out of the water (Bigelow & Schroeder 1953, Rayner 1986). Even with a disc width of up to 7 m and weighing up to 2 t (Marshall et al. 2009), manta rays, Mobula birostris (Walbaum 1792) and M. alfredi (Krefft 1868), can sometimes be observed performing breaching behavior (Marshall & Bennett 2010a, Medeiros et al. 2015, Stevens 2016. ...
ABSTRACT: Improving our knowledge on the behavior of threatened species is essential for developing effective conservation actions. The Paranaguá Estuarine Complex (PEC), southern Brazil, is the only estuary in the world where manta rays have been observed performing breaches seasonally. The exact role of this breaching behavior and the environmental factors connected to it are unknown. Our goals were to determine the spatial distribution, and the temporal and environmental factors that influence the breaching behavior of this endangered group in a dynamic estuarine habitat for the first time. Manta rays were observed breaching in the PEC during austral summer and early autumn, when the sea surface temperature (SST) and precipitation were high. Generalized additive models revealed that the presence and frequency of the breaches were both influenced by the SST and hours of daily effort, while the breaching frequency was also influenced by the wind direction and speed, percentage of moon illumination, and year. The breaches were mainly concentrated near the mouth of a river. Likely these factors influenced not only the occurrence and behavior of manta rays, but also the distribution of their food source, potentially providing optimal conditions for foraging and reproduction. Based on the coloration pattern, it is possible that the observations were of Mobula cf. birostris. These results provide valuable insights into the breaching behavior of manta rays in estuarine waters that will assist future conservation initiatives and research on their behavioral ecology, to optimize fishery management and contribute to developing sustainable ecotourism in the PEC.
... SWA specimens were obtained during trawl-fishing cruises in 2006-2007 and deposited in the Museu Oceanográfico do Vale do Itajaí (MOVI). Skate specimens were identified to species onboard or in the laboratory, using morphological taxonomic characters provided in available identification keys and published guidelines on skate species' morphology [56,57], resulting in a total of 35 nominal species. Skeletal muscle tissue samples were collected from the body ventral surface and stored in 96% ethanol at −20 °C until molecular analyses. ...
Conservation and long-term management plans of marine species need to be based upon the universally recognized key-feature of species identity. This important assignment is particularly challenging in skates (Rajiformes) in which the phenotypic similarity between some taxa and the individual variability in others, hampers accurate species identification. Here, 432 individual skate samples collected from four major ocean areas of the Atlantic were barcoded and taxonomically analysed. A BOLD project ELASMO ATL was implemented with the aim of establishing a new fully available and well curated barcode library containing both biological and molecular information. The evolutionary histories of the 38 skate taxa were estimated with two concatenated mitochondrial markers (COI and NADH2) through Maximum Likelihood and Bayesian inference. New evolutionary lineages within the genus Raja were discovered off Angola, where paleogeographic history coupled with oceanographic discontinuities could have contributed to the establishment of isolated refugia, playing a fundamental role among skates’ speciation events. These data successfully resolved many taxonomic ambiguities, identified cryptic diversity within valid species and demonstrated a highly cohesive monophyletic clustering among the order, laying the background for further inference of evolutionary patterns suitable for addressing management and conservation issues.
The Gulf Stream exerts tremendous influence over oceanographic conditions in the northwestern Atlantic as it transports tropical water to higher latitudes. While the meandering eddies and warm core rings of the Gulf Stream persist year-round, the seasonal warming of coastal waters in the northwestern Atlantic afford many young-of-year tropical and subtropical species temporary refuge through the summer and fall after Gulf Stream dispersal. Several aspects of this dispersal and its impact on coastal ecosystems are difficult to document. Due to the broad scale and intensive sampling effort required to survey these expatriated species, we used a citizen science platform to gather species observations. We analyzed over 1,200 reports of fish from 28 taxonomic families to describe extralimital geographic distributions, observation frequency, and phenological aspects of their dispersal. The influence of ecosystem dynamics and life stage-specific biological characteristics on the observed extralimital distributions of species is discussed. We found that citizen scientists gathered novel sightings relevant to coastal marine fish ecology through a variety of coastal activities, and complimentary to established research methods. These findings support incorporating crowd-sourced data to improve our understanding of marine species assemblages of the northwestern Atlantic.
Many elasmobranch populations were already depleted well before fishery surveys had even started, which means historical investigations are needed to reveal their ignored declines. This is probably the case for the Bramble shark Echinorhinus brucus (Bonnaterre, 1788) whose populations in Europe are suspected of having decreased significantly. In order to document this data deficiency, an inventory
of Bramble shark material that had been preserved in natural history collections, was conducted in the period 2014-2022. A total of 128 collections were contacted around the world, and additional sources of information were traced and consulted (e.g. collection labels, museum registers, digital databases, index cards, pictures, manuscripts and publications). This resulted in a list of 234 entries, subsequently assigned to 169 individual Bramble sharks. These exhibits are, or had been deposited in 80 different collections, spread over 22 countries, whereas the other 48 collections yielded no results. At least 40 entries are presumed lost, so that fewer than 200 entries have been preserved to date, some of them in bad condition. Due to their historic and scientific importance, extensive efforts to preserve
these specimens are more than justified. A significant number of 64 individuals, representing more than 37% of all specimens that were recorded in this survey, have never been published, and are reported here for the first time. Associated geographical data and collection dates are present for nearly all specimens. These ‘new historical records’ can add significantly to our knowledge of the Bramble sharks’ relative abundance and geographical distribution in time. These data will be included in the ongoing Bramble shark Cold Case, a project that will document its suspected decline, and to implement appropriate conservation measures for this iconic, little-known and endangered shark species.
Pliocene fossiliferous exposures at the Lee Creek Mine, Yorktown Formation, deposits yielded 8808 teleost otoliths. These represented at least 45 taxa distributed among 17 teleostean families including the following numbers of species by genus: Agonidae? (1), Ammodytidae (1), Bothidae (2, possibly 3), Branchiostegidae (1), Congridae (5), Cynoglossidae (1), Gadidae (5), Merlucciidae (3), Myctophidae (1), Ophidiidae (7), Pleuronectidae (1), Pomadasyidae (1), Pterothrissidae (1), Sciaenidae (7), Serranidae (4), Triglidae (2, possibly 3), Uranoscopidae (2). Generic names were assigned to 27 kinds of otoliths: Ammodytes, Anisotremus, Astroscopus, Brotula, Centropristis, Ceratoscopelus, Citharichthys, Cynoscion, Diplectrum, Equetus , Gadus, Kathetostoma, Leiostomus, Lepophidium, Lopholatilus, Melanogrammus, Merlangiogadus, Merluccius, Microgadus , Micropogonias, Ophidion, Pogonias, Prionotus , Pterothrissus, Sciaenops , Symphurus, Urophycis . Twenty-two of these represent the first North American Pliocene record for the genus ( Anisotremus , Astroscopus, Brotula, Centropristis, Cynoscion, Diplectrum, Equetus, Gadus, Kathetostoma, Leiostomus, Lepophidium, Lopholatilus, Melanogrammus, Merlangiogadus, Microgadus, Micropogonias, Ophidion, Pogonias, Prionotus, Pterothrissus, Symphurus, Urophycis ). Of these, six represent the initial fossil record anywhere ( Astroscopus, Diplectrum, Equetus, Kathetostoma, Leiostomus, Lopholatilus ). Lopholatilus represents the first fossil record for the family Branchiostegidae. Otoliths from at least two kinds of fish are from extinct genera ( Merlangiogadus and sciaenid species A), and those of the 13 unnamed taxa may represent extinct species. Individuals of all of the listed taxa routinely inhabit waters shallower than 200 meters, except Ceratoscopelus and Merluccius albidus . Based upon the three most abundant kinds of fish otoliths ( Lepophidium, Merluccius , and sciaenid species A), comprising 88 percent of the recovered otoliths, it is suggested that the Lee Creek Mine fauna may have been deposited in depths of 60 to 100 meters.
The feeding ecology of broadbill swordfish (Xiphias gladius) in the California Current was described based on analysis of stomach contents collected by fishery observers aboard commercial drift gillnet boats from 2007 to 2014. Prey were identified to the lowest taxonomic level and diet composition was analyzed using univariate and multivariate methods. Of 299 swordfish sampled (74 to 245 cm eye-to-fork length), 292 non-empty stomachs contained remains from 60 prey taxa. Genetic analyses were used to identify prey that could not be identified visually. Diet consisted mainly of cephalopods but also included epipelagic and mesopelagic teleosts. Jumbo squid (Dosidicus gigas) and Gonatopsis borealis were the most important prey based on the geometric index of importance. Swordfish diet varied with body size, location and year. Jumbo squid, Gonatus spp. and Pacific hake (Merluccius productus) were more important for larger swordfish, reflecting the ability of larger specimens to catch large prey. Jumbo squid, Gonatus spp. and market squid (Doryteuthis opalescens) were more important in inshore waters, while G. borealis and Pacific hake predominated offshore. Jumbo squid was more important in 2007–2010 than in 2011–2014, with Pacific hake being the most important prey item in the latter period. Diet variation by area and year probably reflects differences in swordfish preference, prey availability, prey distribution, and prey abundance. The range expansion of jumbo squid that occurred during the first decade of this century may particularly explain their prominence in swordfish diet during 2007–2010. Some factors (swordfish size, area, time period, sea surface temperature) that may influence dietary variation in swordfish were identified. Standardizing methods could make future studies more comparable for conservation monitoring purposes.
This datasheet on Petromyzon marinus covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
The present paper is a review of the available literature on the significance of forage fish, the plethora of services they provide, and the threats faced by them. Forage fish are pelagic planktivorous species that operate as conduits of energy between the lower trophic level (plankton) and the upper trophic level (predators). A variety of ecosystem services are provided by them, from serving as prey for higher trophic levels to producing fish meal and oil. Forage fish have a consumption value for humans and cultural importance to many societies. Forage fish have faced constant natural and anthropogenic threats in the past, resulting in numerous fish collapses which subsequently impacted their predators. The economic benefit provided by forage fish has been estimated to be approximately $ 18.7 billion per annum. An introspection of the data on ecosystem services revealed lack of data on regulating and cultural services, eventually leading to a monetary underestimation and their commercial prioritization over the wider benefits they provide.
American Shad Alosa sapidissima is an anadromous clupeid that once supported a robust fishery but has declined drastically throughout its native range due to overfishing, dam proliferation, and poor water quality. A hatchery program on the James River in Virginia was introduced in 1992 to support the recovery of stocks. Following a moratorium of the fishery enacted in 1994, a fisheries‐independent survey was initiated in 1998 to monitor the population recovery efforts and status of American Shad stocks in Virginia. This paper examined 22 years of monitoring data for the James River and determined the effect of hatchery inputs on the James River stock of American Shad. The spawning stock index increased from 2.57 in 1998 to a peak of 9.33 in 2003 but has generally been declining since and has been at very low levels in most recent years. The hatchery prevalence for female American Shad (i.e., the percentage of fish derived from the hatchery) ranged between 3.6% and 60.5%. Years with higher spawning stock index values were significantly correlated to higher percentages of hatchery fish returning to spawn. The stock–recruitment relationship was best explained by the Ricker model, which had the lowest residual standard error and Akaike information criterion value. A threshold level of hatchery‐released individuals (approximately 4 million larvae) was necessary to achieve the highest numbers of returning spawners, but stocking above 7 million larvae correlated with declining returns. Long‐term monitoring of the James River American Shad spawning population allowed for the critical examination of the contribution of hatchery individuals to the yearly spawning run and the relative success rate of each hatchery year‐class. From these data, we consider that the James River spawning stock of American Shad was dependent upon hatchery inputs, with ideal hatchery returns occurring during years of moderate levels of hatchery stocking.
Somatic growth is integral to fishery stock productivity. Under climate variability, omitting growth variability renders fishery management strategies non-optimal. Based on a multidecadal tag–recapture database, a case study is presented to investigate the potential growth response of the Atlantic bluefin tuna (Thunnus thynnus) to three regionally relevant large-scale climate patterns: the North Atlantic Oscillation, Arctic Oscillation, and Pacific North America pattern. An additional simulation study is conducted to explore the effect of the overall scale and the distribution of measurement error on the detection probability of extrinsic effects and the estimation of growth parameters. Results indicate significant growth response at an intra-annual scale to all three climate indices examined. Identified growth responses to climate variations are highly nonlinear. The projected growth shows increased growth in recent decades under climate variability with respect to the historical mean. Simulation results show a higher probability to detect climate signals when the overall measurement error is low. Substantial bias is expected when the measurement error at tag release is high, cautioning against careless integration of different types of growth data.
The feeding ecology of broadbill swordfish (Xiphias gladius) in the California Current was described based on analysis of stomach contents collected by federal fishery observers aboard commercial drift gillnet boats from 2007 to 2014. Prey were identified to the lowest taxonomic level and diet composition was analyzed using univariate and multivariate methods. Of 299 swordfish sampled (74 to 245 cm eye-to-fork length), 292 non-empty stomachs contained remains from 60 prey taxa. Diet consisted mainly of cephalopods but also included epipelagic and mesopelagic teleosts. Jumbo squid (Dosidicus gigas) and Gonatopsis borealis were the most important prey based on the geometric index of importance. Swordfish diet varied with body size, location and year. Jumbo squid, Gonatus spp. and Pacific hake (Merluccius productus) were more important for larger swordfish, reflecting the ability of larger specimens to catch large prey. Jumbo squid, Gonatus spp. and market squid (Doryteuthis opalescens) were more important in swordfish diet in inshore waters, while G. borealis and Pacific hake predominated offshore. Jumbo squid was more important from 2007-2010 than in 2011-2014, with Pacific hake the most important prey item in the latter period. Diet variation by area and year probably reflects differences in swordfish preference, prey availability, prey distribution, and prey abundance. The range expansion of jumbo squid that occurred during the first decade of this century may particularly explain their prominence in swordfish diet from 2007-2010. Some factors that may influence dietary variation in swordfish were identified. Standardization could make future studies more comparable for conservation monitoring purposes.
Rainbow Smelt, Osmerus mordax, are a small anadromous species native to the northwest Atlantic Ocean, and populations have declined range wide. A small, mid‐channel survey fyke net is annually deployed to collect demographic information on Rainbow Smelt in several rivers in Massachusetts. Understanding the effectiveness of this fyke net to provide representative data on the spring spawning run is essential for accurate population assessment. To evaluate this effectiveness, we deployed an experimental fyke net that spanned the river channel concurrently with the survey fyke net in the Fore River, Massachusetts from 2009‐2012. The survey net catch‐per‐unit effort increased as the total number of fish increases, but survey net catches are highly variable at lower daily abundances. Differences in size distributions were slight and only significant for females in one of four years. Sex ratios were generally the same between both nets. These findings suggest that while fyke nets might not be ideal for monitoring rivers with very small populations and/or in wide river reaches, catches in larger populations should generally reflect the overall population demographics.
Because the salt concentration of body fluids in aquatic vertebrates differs from that of their environment, they face net influx or efflux of water and salt across their permeable skin or exposed membranes. In fishes, these diffusional movements of both salts and water largely involve the gills. Other vertebrates have less permeable body surfaces, but water and salts are gained in drinking that is incidental to eating prey, which also can be an important source of salt intake. Kidneys function importantly in freshwater fishes to remove excess water, and ions are actively transported inwards across gill tissue as well as acquired in food. Marine fishes tend to dehydrate in seawater, so they drink seawater to make up a water deficit and secrete excess salt across the gills. Marine elasmobranch fishes accumulate urea in body fluids to minimise the gradient for osmotic exchange and secrete excess ions via a specialised rectal gland that functions accessory to the kidney. In other vertebrates, inhabitants of fresh water must counteract a key problem of acquiring sufficient ions while excreting nitrogenous waste as ammonia or urea, whereas marine species must avoid excess salt intake while avoiding dehydration. Vertebrates without gills have evolved either extrarenal salt glands that excrete excess salt, or in the case of mammals, a specialised kidney that can excrete highly concentrated urine. Relatively few, non-fish taxa drink seawater as a route for water gain, while most others have dependency on dietary, metabolic or free drinking water.
• Osmoregulation involves the maintenance of volume, distribution and ionic composition of body fluids in organisms.
• With the exception of hagfish, extant vertebrates maintain osmotic concentrations of body fluids at levels that are roughly one-third that of seawater.
• Aquatic vertebrates living in fresh water must counteract excessive influx of water and losses of ions to the surrounding environment, whereas those living in marine environments tend to dehydrate and gain excess salt.
• Freshwater fishes eliminate excess water by means of producing a copious flow of dilute urine, while acquiring ions from surrounding water by transporter mechanisms located in the gills.
• Marine fishes acquire needed water by drinking seawater and excreting excess salt gained by diffusion and drinking by transport mechanisms in the gills.
• Marine vertebrates other than fishes and mammals have evolved extrarenal salt glands that excrete excess salts, and water is gained largely from dietary, metabolic and freshwater drinking sources.
• Marine mammals excrete salt loads and urea from kidneys that have effective concentrating abilities, while gaining water from diet and metabolism.
The guitarfishes Pseudobatos horkelii and Pseudobatos percellens meet the criteria for threatened status as Critically Endangered (CR) and Endangered (EN), respectively. Both species occur in the Southern Atlantic Ocean. Considering the lack of data on the genetic structure of these species, the present study evaluated the genetic variability and population structure of the P. horkelii and P. percellens in the southern region of Brazil and the northern coast of Argentina, based on sequences of mitochondrial DNA, Control Region (D-loop). Samples of P. horkelii (n = 135) were analyzed in six localities situated in Northern Argentina, along the Brazilian states’ coast. The mean of nucleotide diversity was 0.0053, the ΦST was 0.4277 and demographic analysis of P. horkelii suggests the existence of stability of the populations, with D = 0.9929, FS = 2.0155, SSD = 0.0817, R = 0.2153. In P. percellens (n = 101) were analyzed from six Brazilian localities along the coast of Santa Catarina, Paraná, and São Paulo. The mean nucleotide diversity was 0.0014 and ΦST value of 0.2921, the demographic analysis indicates a high migration rate of P. percellens among the localities evaluated, with D = 0.5222, FS = 0.3528, SSD = 0.01785, R = 0.3890.
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