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At least 37 records · Page 2Linked to original sources
USGS2013

Behavior and movement of adult summer steelhead following collection and release, lower Cowlitz River, Washington, 2012--2013

Executive Summary Historically, adult summer steelhead Oncorhynchus mykiss returning to hatcheries on the lower Cowlitz River were sometimes transported and released in the river (recycled) to provide additional angling opportunity for the popular sport fishery in the basin. However, this practice has not been used in recent years because of concerns associated with interactions between hatchery fish and wild fish. Fishery managers were interested in resuming recycling but lacked information regarding effects of this practice on wild steelhead so we conducted a study during 2012–2013 to: (1) enumerate recycled steelhead that returned to the hatchery or were removed by anglers; and (2) determine if steelhead that were not removed from the river remained in the system where they could interact with wild fish. During June–August 2012, a total of 549 summer steelhead were captured at the Cowlitz Salmon Hatchery, tagged, and released downstream near the Interstate 5 Bridge. All recycled steelhead were tagged with a white Floy ® tag and opercle-punched; 109 (20 percent) of these fish also were radio-tagged. All adult steelhead that return to the hatchery were handled by hatchery staff so recycled steelhead that returned to the hatchery were enumerated daily. A creel survey and voluntary angler reports were used to determine the number of recycled steelhead that were caught by anglers. We established three fixed telemetry monitoring sites on the mainstem Cowlitz River and eight additional sites were deployed on tributaries to the lower Cowlitz River where wild winter steelhead are known to spawn. We also conducted mobile tracking from a boat during October 2012, November 2012, and January 2013 to locate radio-tagged fish. A total of 10,722 summer steelhead were captured at the Cowlitz Salmon Hatchery in 2012, which was the largest return since 2008. River flows during much of the study period were similar to 2008–2011 average flows, however, high-flow periods in July and November 2012 were nearly twice as high as the 2008–2011 average flows. We determined that 50 percent (273 fish) of the recycled steelhead returned to the hatchery and 18 percent (102 fish) of the recycled steelhead were caught by anglers. Most (243 fish; 89 percent) of the recycled steelhead that returned to the hatchery were recollected during July–August. The average elapsed time from release to recapture at the hatchery was 9 days (d) and 72 percent (182 fish) of the fish returned to the hatchery within 14 d of release. These trends were similar for recycled steelhead that were caught by anglers. Most fish were caught during July–August and the median time from release to capture was 10 d. We determined that 65 percent (70 fish) of the angler-caught fish returned to the hatchery within 14 d of release. River flows appeared to affect both hatchery returns and angler catch. The daily number of recycled steelhead that were recollected at the hatchery were low during periods when river flows were decreasing and high during periods when river flows were increasing. Conversely, daily angler catch of recycled steelhead generally was low when flows were increasing and high when flows were decreasing. We determined that 32 percent of the recycled steelhead (174 fish) were not removed from the lower Cowlitz River, based on observations from hatchery returns and angler reports, but results from the radio-tagged fish were insightful for understanding what may have happened to these fish. By comparison, we determined that 24 percent of the radio-tagged fish were not known to have been removed from the river. We determined that 12 percent of these fish were actively moving in the lower Cowlitz River during October 2012–January 2013. None of the radio-tagged fish were detected in tributaries during the study period except for a single fish that spent approximately 7 d in the Toutle River during early September. During October 2012–January 2013, 10 percent of the radio-tags from recycled steelhead were detected near popular fishing areas, and 2 percent of the radio-tagged steelhead were never detected during the study period. We suspect that a large proportion of these fish may have been harvested and not reported, or died. Detection patterns of radio-tagged steelhead showed that most fish (82 percent) moved upstream from the release site and were detected at the Trout Hatchery and the Barrier Dam sites. The median time from release to detection at these sites was 3.7 d and many of these fish made multiple trips between the two sites. Nearly one-third (29 percent) of the recycled steelhead that were detected at the Trout Hatchery and the Barrier Dam made at least two trips between the sites and some fish made as many as six trips. Radio-tagged fish that remained in the lower Cowlitz River during the spawning period (December 2012–January 2013) were observed in the river reach between the mouth of Ostrander Creek (river mile 10) and the Trout Hatchery (river mile 44). During this study, we collected data on opercle punch regrowth rates to understand the temporal effectiveness of this marking technique. We took opercle measurements for a total of 190 fish during the study. Fresh opercle punches were measured for 63 fish at the time of marking, and the remaining 127 fish were measured when fish returned to the hatchery. We determined that opercle punches remained open for about 30 d. The holes appeared to regrow slowly in the first 20 d after marking, but regrowth accelerated during the 20–30 d post-marking period. After 30 d, all opercle punches that we observed had completely closed due to tissue regrowth. Our study showed that a large proportion (68 percent) of the recycled steelhead were removed from the lower Cowlitz River. These fish primarily entered the hatchery or were caught by anglers within 14 d of release, which suggests that they present minimal risk to wild fish in the system. However, the remaining fish (32 percent) could not be accounted for, which may complicate fisheries management decisions associated with recycling summer steelhead. Findings from the radiotelemetry study suggest that unreported harvest or mortality could explain a large proportion of those fish that were not reported as having been removed from the river. Furthermore, intensive monitoring of the key spawning tributaries failed to detect a single fish during the spawning period. These findings were supported by observations from weir traps operated by the Washington Department of Fish and Wildlife. Our findings indicate that additional research may be warranted to further examine the effects of recycling hatchery summer steelhead in the lower Cowlitz River.

Washington↗
USGS2001

Fish species and community distributions as proxies for sea-floor habitat distributions: the Stellwagen Bank National Marine Sanctuary example (northwest Atlantic, Gulf Of Maine)

Defining the habitats of fishes and associated fauna on outer continental shelves is problematic given the paucity of data on the actual types and distributions of seafloor habitats. However many regions have good data on the distributions of fishes from resource surveys or catch statistics because of the economic importance of the fisheries. Fish distribution data (species or communities) have been used as a proxy for the distribution of habitats to develop precautionary conservation strategies for habitat protection (e.g., marine protected areas, fishing gear restrictions). In this study we assessed the relationships between the distributions of fish communities and species derived from trawl survey data with the spatial distribution of sediment types determined by sampling and acoustic reflectance derived from multibeam sonar surveys in Stellwagen Bank National Marine Sanctuary. Fish communities were correlated with reflectance values but all communities did not occur in unique sediment types. This suggests that use of community distributions as proxies for habitats should include the caveat that a greater number of communities within an area could indicate a greater range of habitat types. Single species distributions showed relationships between abundance and reflectance values. Trawl catches with low abundances had wide variations in reflectance values while those with high abundances had narrower ranges indicating habitat affinities. Significant non-random frequency-dependent relationships were observed for 17 of 20 species although only 12 of 20 species had significant relationships based on rank correlation. These results suggest that species distributions based on trawl survey data can be used as proxies for the distribution of seafloor habitats. Species with known habitat associations can be used to infer habitat requirements of co-occurring species and can be used to identify a range of habitat types.

Massachusetts↗
USGS2006

Causes of mortality in California sea otters during periods of population growth and decline

Elevated mortality appears to be the main reason for both sluggish growth and periods of decline in the threatened California sea otter population . We assessed causes of mortality from salvage records of 3,105 beach-cast carcasses recovered from 1968 through 1999, contrasting two periods of growth with two periods of decline . Overall, an estimated 40%-60% of the deaths were not recovered and 70% of the recovered carcasses died from unknown causes . Nonetheless, several common patterns were evident in the salvage records during the periods of population decline . These included greater percentages of (1) prime age animals (3-10 yr), (2) carcasses killed by great white shark attacks, (3) carcasses recovered in spring and summer, and (4) carcasses for which the cause of death was unknown. Neither sex composition nor the proportion of carcasses dying of infectious disease varied consistently between periods of population increase and decline . The population decline from 1976 to 1984 was likely due to incidental mortality in a set-net fishery, and the decline from 1995 to 1999 may be related to a developing live-fish fishery. Long-term trends unrelated to periods of growth and decline included a decrease in per capita pup production and mass/length ratios of adult carcasses over the 31-yr study. The generally high proportion of deaths from infectious disease suggests that this factor has contributed to the chronically sluggish growth rate of the California sea otter population .

California↗
USGS2022

African penguins and localized fisheries management: Response to Butterworth and Ross-Gillespie

We present a response to Butterworth and Ross-Gillespie's (2022) comment on our perspectives on how forage fish fisheries are impacting the endangered African penguin ( Sphenicus demersus ), and corresponding management options. Butterworth and Ross-Gillespie overstate model uncertainties and downplay the clear ecological and conservation significance of the fisheries closure experiment. We demonstrate that their criticism of “pseudo-replication” is weak, and not in line with their own analyses nor with the interpretations of many international scientific review panels commissioned by the government of South Africa to evaluate experimental results. Their comment does not alter our fundamental conclusions that forage fisheries operating near penguin breeding colonies compete with the birds for food resources, are detrimental to the penguin's population health, and are impeding recovery. Given that sardines are depleted (DFFE, 2021) and the African penguin is approaching a conservation crisis, we reiterate our position that continuing the precautionary approach of closures at the local scale of central-place foraging penguins is warranted to facilitate their population growth under fisheries management goals to conserve and maintain ecosystem functions.

ICES Journal of Marine Science↗
USGS2006

Virus diseases of the salmonidae in the western United States. I. Etiology and epizootiology

The history of fish diseases in western United States shows an increasing awareness that viruses could cause epizootics in fish. Fishery biologists bunked first, for protozoan and metazoan parasites, then for bacteria, and if none could be identified assumed that the mortalities were attributable to nutritional deficiency, Microbiologists in general were cognizant of virus diseases in other animals and investigators of fish diseases were alert to the possibility that piscine epizootics could be of similar cause. In 1950 an epizootic occurred in sockeye salmon (Gncorhynchus norkm) that was shown to have a viral etiologic agent. In recent years, with increasing frequency, we have been able to demonstrate a virus utiology for epizootics and panzootics in trout and salmon in several states in the West. FIGURE 1 is a map showing the location of epizootics of infectious pancreatic necrosis (IPN), Sacramento River chinook disease (SRCD), Oregon sockeye disease (OSD), and Columbia River sockeye disease (CRSDJ. The pathology and immunopathology of these are discussed in detail in other reports. The present report was initiated as a review of the literature concerning the diseases and to present in brief a description of their etiologic agents.

Annals of the New York Academy of Sciences↗
USGS2025

Three decades of World Recreational Fishing Conferences: What have we learned about the dynamics of recreational fisheries?

Recreational fishing extends beyond catching fish, connecting individuals with nature, generating environmental stewards and contributing significantly to both local, regional and national economies. Assessing potential impacts on ecosystems and social-ecological systems requires dedicated multi- and interdisciplinary research and integrative management and policy approaches. Managing recreational fisheries effectively also necessitates transdisciplinary thinking, yet this poses continued challenges, as researchers and managers balance specialized expertise with innovative, boundary-crossing perspectives in light of limited funding in a rapidly changing social-ecological environment. The World Recreational Fishing Conference (WRFC) serves as the leading global scientific forum for addressing these challenges, fostering interdisciplinary exchange among scientists, managers, policy makers and stakeholders. The papers in this special issue represent the output of the last WRFC in Melbourne, Australia in 2023. By reviewing the content of the papers published in the present special issue, we illustrate the critical role of collaborative spaces, such as the WRFC, in bridging different expertise and approaches and fostering innovation, thereby securing adaptive management and conservation of recreational fisheries in response to global changes. Evaluating the development of the WRFC over three decades highlights how this conference series represents a leading think tank serving the entire network of recreational fisheries professionals globally.

Fisheries Management and Ecology↗
USGS2025

Lake Superior fish community and fisheries, 2001–2022: An era of stability

Lake Superior is the least anthropogenically impacted of the Laurentian Great Lakes ecosystems, yet dramatic changes to the fish community are evident. Previous published works chronicled those changes and the efforts to rehabilitate the fish community through the year 2000. Here, we review through the year 2022, where post-rehabilitation stability was driven by lean lake trout ( Salvelinus namaycush namaycush) as the most abundant piscivore in nearshore waters, siscowet lake trout ( Salvelinus namaycush siscowet) as the most abundant piscivore in offshore waters, and a healthy, intact assemblage of native prey species, which created ecological redundancies and helped stabilize the food web. Stocking of non-native salmonines was reduced 74%, and populations of Chinook salmon ( Oncorhynchus tshawytscha) and coho salmon ( Oncorhynchus kisutch) were maintained through natural reproduction. Despite reduced stocking, yield from recreational fisheries was stable. Likewise, developments in population modeling led to evaluations and refinement of management strategies that helped create stability for lake trout, lake whitefish ( Coregonus clupeaformis ), and cisco ( Coregonus artedi ) fisheries. With lake trout rehabilitation achieved, focus shifted toward rehabilitation of native brook trout ( Salvelinus fontinalis ), lake sturgeon ( Acipenser fulvescens ), and walleye ( Sander vitreus ). Despite continued control efforts, sea lamprey ( Petromyzon marinus ) abundance increased considerably, and estimates of fish killed by lampreys averaged 2.65 million kg annually. Environmental changes have benefited sea lampreys and fostered thermal habitats more suitable to non-native organisms, posing new challenges for managers and researchers. Nevertheless, the post-rehabilitation stability in the contemporary fish community will help provide resilience to future perturbations in the ecosystem.

Lake Superior↗
USGS2001

Management of Pacific herring closed pound spawn-on-kelp fisheries to optimize fish health and product quality

Use of high densities of newly recruited Pacific herring Clupea pallasi for the closed-pound spawn-on-kelp (PPSOK) fishery in Prince William Sound, Alaska, was associated with increased gamete retention, decreased product quality, and increased prevalence of viral hemorrhagic septicemia virus (VHSV) relative to the confinement of older cohorts at lower densities. To maximize product quality and reduce the potential for disease outbreaks, three management alternatives are proposed for the PPSOK fishery: (1) establish minimum pound volumes per permit holder; (2) prohibit PPSOK fisheries during years predominated by newly recruited cohorts; and (3) develop effective open-pounding techniques.

North American Journal of Fisheries Management↗
USGS2009

Fishing mortality in North Carolina's southern flounder fishery: direct estimates of instantaneous fishing mortality from a tag return experiment

Estimation of harvest rates is often a critical component of fishery stock assessment and management. These assessments are often based on catch-at-age data sets generated over many years, but estimates of instantaneous fishing mortality ( F ) can also be obtained from a shorter-term tag return study. We conducted a 2-year tag return experiment to generate direct estimates of F for southern flounder Paralichthys lethostigma in a North Carolina estuary. The southern flounder supports lucrative commercial and recreational fisheries within the state and has experienced heavy fishing pressure for more than a decade. During 2005 and 2006, fish were captured and tagged with the assistance of commercial harvesters in the New River estuary. Tag returns were used to generate monthly estimates of F , which demonstrated a clear seasonal pattern that was consistent between years. Several important assumptions of the tag return model were accounted for through the use of double-tagged individuals, the distribution of both high- and standard-reward tags, and the completion of an independent controlled experiment to evaluate mortality related to tagging. Annual estimates of F exceeded the short-term management target in both years. Residual patterns suggest that the estimates may actually have been biased low, possibly due to delayed mixing of tagged fish. Thus, despite recently amended fishery regulations, F in the North Carolina southern flounder gill-net fishery still has the potential to greatly exceed targeted levels, which may delay stock recovery. Tag return studies can provide reliable (and nearly real-time) information about F and natural mortality as long as the experimental design addresses specific assumptions related to tagging-induced mortality, tag shedding, and nonreporting of tags.

North Carolina↗
USGS2018

An underwater observation dataset for fish classification and fishery assessment

Using Dual-Frequency Identification Sonar (DIDSON), fishery acoustic observation data was collected from the Ocqueoc River, a tributary of Lake Huron in northern Michigan, USA. Data were collected March through July 2013 and 2016 and included the identification, via technology or expert analysis, of eight fish species as they passed through the DIDSON’s field of view. A set of short DIDSON clips containing identified fish was curated. Additionally, two other datasets were created that include visualizations of the acoustic data and longer DIDSON clips. These datasets could complement future research characterizing the abundance and behavior of valued fishes such as walleye ( Sander vitreus ) or white sucker ( Catostomus commersonii ) or invasive fishes such as sea lamprey ( Petromyzon marinus ) or European carp ( Cyprinus carpio ). Given the abundance of DIDSON data and the fact that a portion of it is labeled, these data could aid in the creation of machine learning tools from DIDSON data, particularly for invasive sea lamprey which are amply represented and a destructive invader of the Laurentian Great Lakes.

Scientific Data↗
USGS2004

Relationships between bald eagle productivity and dynamics of fish populations and fisheries in the Wisconsin waters of Lake Superior, 1983-1999

Bald eagle ( Haliaeetus leucocephalus ) abundance declined in the 1950s and 1960s along the Wisconsin waters of Lake Superior, and were nearly absent along Wisconsin's Lake Superior shoreline. The population began to increase again between 1980 and 1983, and since then bald eagles nesting on islands along Wisconsin's Lake Superior shoreline (i.e., Apostle Islands ) reproduced at a lower rate than have those nesting along the mainland shoreline of the lake and inland. Recent research indicated that bioaccumulation of toxic chemicals in the aquatic food chain no longer limits bald eagle reproduction there, and that productivity at island nests was lower than at mainland nests and inland nests as the result of low food availability. Management agencies have sought models that accurately predict productivity and explain ecological relationships, but no satisfactory models had previously been developed. Modeling was conducted here to determine which factors best explained productivity variability. The Ricker stock-recruitment model derived from only the bivariate breeding pair and productivity data explained only 1% of the variability in productivity data. The functional relationship that explained the greatest amount of productivity variation (83%) included the number of breeding pairs, burbot ( Lota lota ) biomass, longnose sucker ( Catostomus catostomus ) biomass, and commercial harvest of nontarget fishes. Model results were interpreted to mean that productivity was positively affected by populations of burbot and longnose sucker, which are important prey items, and by commercial fishermen feeding nontarget fish to bald eagles. Harvest of nontarget fishes by tribal fishermen and burbot and longnose sucker populations have not tended to change during the entire study period, although the burbot population has declined since 1991. Therefore, bald eagle productivity is not predicted to increase unless burbot, longnose sucker, or other preferred prey of bald eagles increases in the Apostle Islands.

Wisconsin↗
USGS2023

Towards vibrant fish populations and sustainable fisheries that benefit all: Learning from the last 30 years to inform the next 30 years

A common goal among fisheries science professionals, stakeholders, and rights holders is to ensure the persistence and resilience of vibrant fish populations and sustainable, equitable fisheries in diverse aquatic ecosystems, from small headwater streams to offshore pelagic waters. Achieving this goal requires a complex intersection of science and management, and a recognition of the interconnections among people, place, and fish that govern these tightly coupled socioecological and sociotechnical systems. The World Fisheries Congress (WFC) convenes every four years and provides a unique global forum to debate and discuss threats, issues, and opportunities facing fish populations and fisheries. The 2021 WFC meeting, hosted remotely in Adelaide, Australia, marked the 30th year since the first meeting was held in Athens, Greece, and provided an opportunity to reflect on progress made in the past 30 years and provide guidance for the future. We assembled a diverse team of individuals involved with the Adelaide WFC and reflected on the major challenges that faced fish and fisheries over the past 30 years, discussed progress toward overcoming those challenges, and then used themes that emerged during the Congress to identify issues and opportunities to improve sustainability in the world's fisheries for the next 30 years. Key future needs and opportunities identified include: rethinking fisheries management systems and modelling approaches, modernizing and integrating assessment and information systems, being responsive and flexible in addressing persistent and emerging threats to fish and fisheries, mainstreaming the human dimension of fisheries, rethinking governance, policy and compliance, and achieving equity and inclusion in fisheries. We also identified a number of cross-cutting themes including better understanding the role of fish as nutrition in a hungry world, adapting to climate change, embracing transdisciplinarity, respecting Indigenous knowledge systems, thinking ahead with foresight science, and working together across scales. By reflecting on the past and thinking about the future, we aim to provide guidance for achieving our mutual goal of sustaining vibrant fish populations and sustainable fisheries that benefit all. We hope that this prospective thinking can serve as a guide to (i) assess progress towards achieving this lofty goal and (ii) refine our path with input from new and emerging voices and approaches in fisheries science, management, and stewardship.

Reviews in Fish Biology and Fisheries↗
USGS2005

Evaluating and understanding fish health risks and their consequences in propagated and free-ranging fish populations

Fishery managers and resource conservationists are increasingly interested in understanding the fish health and disease risks of free-ranging fishes and whether propagated fishes or features and practices used at fish culture facilities pose a health risk to free-ranging populations. Disease agents are present in most both captive and all free-ranging fish populations, but the consequences and extent of infections in free-ranging populations are often difficult to measure, control, and understand. Sampling methods, protocols, and assay techniques developed to assess the health of captive populations are not as applicable for assessments of free-ranging fishes. The use of chemicals and therapeutics to control diseases and parasites in propagated fishes likely reduces the risk of introducing specific pathogens into the environment, but control measures may have localized effects on the environment surrounding fish culture facilities. To understand health risks of propagated and free ranging fishes, we must consider fish populations, culture facilities, fish releases, and their interactions within the greater geospatial features of the aquatic environment. ?? 2004 by the American Fisheries Society.

American Fisheries Society Symposium↗
USGS2012

Western Fisheries Research Center--Forage fish studies in Puget Sound

Researchers at the Western Fisheries Research Center are working with other U.S. Geological Survey (USGS) Centers to better understand the interconnected roles of forage fishes throughout the ecosystem of Puget Sound, Washington. Support for these studies primarily is from the USGS Coastal Habitats in Puget Sound (CHIPS) program, which supports studies of the nearshore areas of Puget Sound. Human perturbations in the nearshore area such as shoreline armoring or urban development can affect the nearshore habitats critical to forage fish.

Washington↗
USGS2012

Benefits and risks of adopting the global code of practice for recreational fisheries

Recreational fishing constitutes the dominant or sole use of many fish stocks, particularly in freshwater ecosystems in Western industrialized countries. However, despite their social and economic importance, recreational fisheries are generally guided by local or regional norms and standards, with few comprehensive policy and development frameworks existing across jurisdictions. We argue that adoption of a recently developed Global Code of Practice (CoP) for Recreational Fisheries can provide benefits for moving recreational fisheries toward sustainability on a global scale. The CoP is a voluntary document, specifically framed toward recreational fisheries practices and issues, thereby complementing and extending the United Nation's Code of Conduct for Responsible Fisheries by the Food and Agricultural Organization. The CoP for Recreational Fisheries describes the minimum standards of environmentally friendly, ethically appropriate, and—depending on local situations—socially acceptable recreational fishing and its management. Although many, if not all, of the provisions presented in the CoP are already addressed through national fisheries legislation and state-based fisheries management regulations in North America, adopting a common framework for best practices in recreational fisheries across multiple jurisdictions would further promote their long-term viability in the face of interjurisdictional angler movements and some expanding threats to the activity related to shifting sociopolitical norms.

Fisheries↗
USGS2014

Using posts to an online social network to assess fishing effort

Fisheries management has evolved from reservoir to watershed management, creating a need to simultaneously gather information within and across interacting reservoirs. However, costs to gather information on the fishing effort on multiple reservoirs using traditional creel methodology are often prohibitive. Angler posts about reservoirs online provide a unique medium to test hypotheses on the distribution of fishing pressure. We show that the activity on an online fishing social network is related to fishing effort and can be used to facilitate management goals. We searched the Nebraska Fish and Game Association Fishing Forum for all references from April 2009 to December 2010 to 19 reservoirs that comprise the Salt Valley regional fishery in southeastern Nebraska. The number of posts was positively related to monthly fishing effort on a regional scale, with individual reservoirs having the most annual posts also having the most annual fishing effort. Furthermore, this relationship held temporally. Online fishing social networks provide the potential to assess effort on larger spatial scales than currently feasible.

Nebraska↗
USGS2019

Fish assemblage structure and fisheries resources in Puerto Rico’s riverine estuaries

Tropical estuaries are diverse and productive habitats with respect to their fish assemblages and associated fisheries, but these ecosystems and fisheries are imperiled by multiple anthropogenic threats. Despite the economic, social, and biodiversity value of tropical estuarine fish assemblages, they are poorly understood, especially those on Caribbean islands. We sampled the fish assemblages of four estuaries that were broadly representative of riverine estuaries in Puerto Rico, including the Río Grande de Arecibo, Río Espiritu Santo, Río Mameyes, and Río Sabana. We used a combination of passive (gill nets) and active (seine) gears at locations that spanned the salinity gradient of each estuary during July–October 2013–2014 (rainy season) and March 2015 (dry season). Fish species richness among the riverine estuaries varied from 18 to 29 and was highest in the Río Espiritu Santo estuary. Nonmetric multidimensional scaling differentiated fish assemblages among estuaries but not by season or consistently by location within an estuary. Spearman's rank correlation analysis also revealed dissimilarity among each estuary's fish assemblage, as most pairwise correlations between the species compositions were not significant. We identified common and widespread species among estuaries, including sport fishes, such as the Tarpon Megalops atlanticus and Common Snook Centropomus undecimalis . As the only multi‐river assessment of riverine estuary fish assemblages in Puerto Rico, our results provide the best available information about the spatial variability of assemblages and fisheries resources. This information will benefit future conservation and fisheries management efforts, which are needed due to increasing anthropogenic impacts, such as illegal harvest, invasive species, and water diversions.

Puerto Rico↗