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At least 91 records · Page 5Linked to original sources
USGS2017

Food-web dynamics and isotopic niches in deep-sea communities residing in a submarine canyon and on the adjacent open slopes

Examination of food webs and trophic niches provide insights into organisms' functional ecology, yet few studies have examined trophodynamics within submarine canyons, where the interaction of canyon morphology and oceanography influences habitat provision and food deposition. Using stable isotope analysis and Bayesian ellipses, we documented deep-sea food-web structure and trophic niches in Baltimore Canyon and the adjacent open slopes in the US Mid-Atlantic Region. Results revealed isotopically diverse feeding groups, comprising approximately 5 trophic levels. Regression analysis indicated that consumer isotope data are structured by habitat (canyon vs. slope), feeding group, and depth. Benthic feeders were enriched in 13 C and 15 N relative to suspension feeders, consistent with consuming older, more refractory organic matter. In contrast, canyon suspension feeders had the largest and more distinct isotopic niche, indicating they consume an isotopically discrete food source, possibly fresher organic material. The wider isotopic niche observed for canyon consumers indicated the presence of feeding specialists and generalists. High dispersion in δ 13 C values for canyon consumers suggests that the isotopic composition of particulate organic matter changes, which is linked to depositional dynamics, resulting in discrete zones of organic matter accumulation or resuspension. Heterogeneity in habitat and food availability likely enhances trophic diversity in canyons. Given their abundance in the world's oceans, our results from Baltimore Canyon suggest that submarine canyons may represent important havens for trophic diversity.

Baltimore Canyon↗
USGS2017

Diet composition and provisioning rates of nestlings determine reproductive success in a subtropical seabird

Understanding how both quality and quantity of prey affect the population dynamics of marine predators is a crucial step toward predicting the effects of environmental perturbations on population-level processes. The Junk Food Hypothesis, which posits that energetic content of prey species may influence reproductive capacity of marine top predators regardless of prey availability, has been proposed as a mechanism by which changes in prey populations could affect predator populations in high latitude systems; however, support for this hypothesis has been inconsistent across studies, and further data are needed to elucidate variation in the relative importance of prey quantity and quality, both among predator species and across ecological systems. We tested the relative importance of prey quantity and quality to nestling survival in the eastern brown pelican Pelecanus occidentalis carolinensis across 9 breeding colonies in the northern Gulf of Mexico that varied in underlying availability of a key prey resource, the Gulf menhaden Brevoortia patronus . Both feeding frequency and meal mass were significantly correlated to energy provisioning rates and nestling survival, while energy density of meals had little effect on either metric. Compared to previous results from cold-water systems, we found lower and less variable energy densities (4.4 kJ g -1 , vs. 5.2 to 6.5 kJ g -1 in other studies) and lipid content (9% dry mass, vs. 16 to 23% in other studies) of common prey items. While Gulf menhaden was the most common prey species at all colonies, the proportion of menhaden fed to nestlings varied and was not strongly correlated to fledging success. We conclude that quantity rather than quality of prey, particularly small schooling fish, is the main driver of brown pelican reproductive success in this system, and that environmental perturbations affecting biomass, distribution, and abundance of forage fish could substantially affect brown pelican reproductive success.

Gulf of Mexico↗
USGS2018

Three-dimensional foraging habitat use and niche partitioning in two sympatric seabird species, Phalacrocorax auritus and P. penicillatus

Ecological theory predicts that co-existing, morphologically similar species will partition prey resources when faced with resource limitations. We investigated local movements, foraging dive behavior, and foraging habitat selection by breeding adults of 2 closely related cormorant species, double-crested cormorants Phalacrocorax auritus and Brandt’s cormorants P. penicillatus . These species nest sympatrically at East Sand Island in the Columbia River estuary at the border of Oregon and Washington states, USA. Breeding individuals of each species were tracked using GPS tags with integrated temperature and depth data-loggers. The overall foraging areas and core foraging areas (defined as the 95% and 50% kernel density estimates of dive locations, respectively) of double-crested cormorants were much larger and covered a broader range of riverine, mixed-estuarine, and nearshore marine habitats. Brandt’s cormorant foraging areas were less expansive, were exclusively marine, and mostly overlapped with double-crested cormorant foraging areas. Within these areas of overlap, Brandt’s cormorants tended to dive deeper (median depth = 6.48 m) than double-crested cormorants (median depth = 2.67 m), and selected dive locations where the water was deeper. Brandt’s cormorants also utilized a deeper, more benthic portion of the water column than did double-crested cormorants. Nevertheless, the substantial overlap in foraging habitat between the 2 cormorant species in the Columbia River estuary, particularly for Brandt’s cormorants, suggests that superabundant prey resources allow these 2 large and productive cormorant colonies to coexist on a single island near the mouth of the Columbia River.

Marine Ecology Progress Series↗
USGS2018

Selective occupancy of a persistent yet variable coastal river plume by two seabird species

Advances in telemetry and modeling of physical processes expand opportunities to assess relationships between marine predators and their dynamic habitat. The Columbia River plume (CRP) attracts sooty shearwaters Ardenna grisea and common murres Uria aalge , but how seabirds respond to variability in plume waters is unknown. We characterized seabird distributions in relation to hourly, daily, monthly, and seasonal variation in CRP location and surface area by attaching satellite telemetry tags to shearwaters in 2008 and 2009, and to murres in 2012 and 2013. We matched seabird locations to surface salinity from a high-resolution hydrodynamic model of the CRP and adjacent waters. Utilization distributions indicated high-use areas north of the Columbia River mouth and in continental shelf waters. Shearwater and murre occupancy of tidal (<21 psu), recirculating (21-26 psu), and boundary (26-31 psu) plume waters was on average 31% greater than expected and positively correlated with CRP surface area. Seabird latitude was positively correlated with latitude of the geographic center of the CRP, indicating that birds move in phase with the plume. We detected a threshold response of seabirds to plume size, and birds were closer to the convergent CRP boundary (28 psu isohaline) after a surface area threshold between 1500 and 4000 km 2 was exceeded. We conclude that shearwaters and murres selectively occupy and track plume waters, particularly dynamic boundary waters where foraging opportunities may be enhanced by increases in surface area and associated biophysical coupling that aggregates zooplankton and attracts prey fishes.

Marine Ecology Progress Series↗
USGS1995

Direct denitrification in mangrove sediments in Terminos Lagoon, Mexico

Rates of direct denitrification were measured using 15 N isotope tchniques in intact sediment cores from fringe and basin mangroves in Terminos Lagoon, Mexico. Sediments were injected with 15 NO 3 - and the distribution of 15 N was measured over time in the head space, overlying water, and sediments. Experiments included an investigation of spatial variation in denitrification rates by comparing results from the fringe and basin mangroves in the rainy season (July 1991); a second experiment was to determine the effect of 3 different NO 3 - concentrations (25, 100, 200 umol core -1 15 N-KNO 3 - ) on denitrification rates and was performed in the fringe mangrove during the 'Norte' season (January 1992). Highest 15 N-N 2 fluxes were measured in the fringe mangrove at 9.4 umol m -2 h -1 , while denitrification rates in the basin mangrove ranged from 1.9 to 4.5 umol m -2 h -1 . 15 N-N 2 fluxes in sediment cores from the fringe mangrove were significantly higher (4.5 to 7.7 umol m -2 h -1 ) in cores enriched with 200 umol core -1 15 N-KNO 3 - compared to cores enriched with 25 and 100 umol core -1 15 N-KNO 3 - (<1 umol m -2 h -1 ). Most of the applied 15 N was recovered as particulate nitrogen in the sediment and a small fraction reduced to NH 4 + in both experiments. The low denitrification rates observed in the fringe and basin mangroves indicate that the capacity for sediment denitrification is limited by low NO 3 - availability. Previous nutrient exchange studies concluded that the fringe mangrove was a 'sink' of NO 3 - since sediment uptake of NO 3 - was assumed lost through denitrification. Results from this study show <10% of sediment NO 3 - uptake in fringe mangroves may be lost to denitrification; the remainder being immobilized in the sediment.

Terminos Lagoon↗
USGS2018

Post-fledging survival of Adélie Penguins at multiple colonies: chicks raised on fish do well

We assessed whether the mass of Adélie penguin Pygoscelis adeliae fledglings at 3 colonies of markedly disparate size on Ross Island, Ross Sea, correlated with their eventual return as subadults. We compared our results with those from Anvers Island, Bellingshausen Sea. Colony sizes at Ross Island have been increasing, contrary to decreasing size at Anvers Island. At Ross Island, during the month prior to fledging, chick diet consisted equally of energy-dense Antarctic silverfish Pleuragramma antarctica and less-caloric crystal krill Euphausia crystal-lorophias , while at Anvers Island the diet was principally Antarctic krill E. superba . At Ross Island, the mass of fledglings who subsequently returned (mean ± SE: 3.4 ± 0.0411 kg) exceeded that of those not seen again (3.2 ± 0.0251 kg), compared to Anvers Island (3.2 vs. 3.0 kg, respectively). At Ross Island, fledging mass was inversely related to colony size and, at the largest colony, fledging mass decreased as the colony grew. Average mass of returnees at the largest colony was less than the mass at Anvers Island for those fledglings that did not return. The mean proportion of fish in the chicks’ diet decreased at the largest Ross Island colony over time, as did fledging mass. We hypothesize that intraspecific competition increased along with colony size, decreasing the availability of fish. We further hypothesize that at the large Ross Island colony, post-fledging penguins must be finding adequate prey, and more energy-dense fish, just outside the colony’s foraging area to explain opposing trends in colony trajectories.

Beaufort Island, Ross Island, Ross Sea↗
USGS2018

Shared habitat use by juveniles of three sea turtle species

The first step in understanding how sympatric species share habitat is defining spatial boundaries. While home range data for juvenile sea turtles exists, few studies have examined spatial overlap of multiple species in foraging habitat. Using satellite tracking technology, we define home ranges for juveniles of 3 sea turtle species (loggerhead, Kemp’s ridley, and green; n = 21) captured at 2 adjacent foraging sites in the northern Gulf of Mexico. In these areas, green turtles are known to be primarily herbivorous, whereas Kemp’s ridley turtles forage predominately on crabs, and loggerhead turtles on various hard-shelled benthic invertebrates. No differences in home range size or characteristics, such as water depth and distance to shore, were observed among species, although fine-scale foraging patches were not examined in this study. A high degree of overlap in habitat-use among all 3 species was documented in summer at both sites. Seasonal movements, triggered by colder winter temperatures, were documented and appeared to differ among species, with Kemp’s ridley and loggerhead turtles leaving bays, and green turtles overwintering inside bays. By identifying shared habitat-use by juvenile sea turtles, we have created a foundation for further fine-scale studies on resource partitioning that will aid in habitat management and conservation of these threatened and endangered species.

Marine Ecology Progress Series↗
USGS2019

Predation strategies of larval clownfish capturing evasive copepod prey

Fish larvae depend on finding and capturing enough prey for rapid growth during the planktonic phase. The diet of many fish larvae is dominated by copepods, small crustaceans that are highly sensitive to hydrodynamic disturbances and possess strong escape responses. We examined how fish larvae with immature jaws, musculature and fins capture such evasive prey. The kinematics of feeding attempts by larval clownfish Amphiprion ocellaris on 3 developmental stages of copepod Bestiolina similis were investigated using high-speed videography. A stealthy approach brought the fish larva within ~1 mm of the copepod; shortest distances were observed in early larvae (1 to 5 d post-hatch [dph]) attacking immature copepods. Peak speeds during strikes increased with fish age and copepod developmental stage (150 to 250 mm s -1 ), with time to capture <8 ms on average. Most successful captures (70%) were of copepods that failed to initiate an escape response during the strike. If a copepod initiated an escape, capture success decreased to ~50% for nauplii and copepodites and 25% for adults. Adult copepods were more likely to attempt an escape response than copepodites or nauplii. Prey stage and the interaction between strike distance and speed were the parameters that best fit a logistic regression model to the observed captures and escapes. The successful switch to larger and more evasive copepod prey by A. ocellaris larvae did not occur until 7 dph and coincided with ontogenetic changes (post-flexion) and a predatory strategy that included shorter approach phases and greater strike speeds.

Marine Ecology Progress Series↗
USGS2019

Extreme reduction in nutritional value of a key forage fish during the Pacific marine heatwave of 2014–2016

Pacific sand lance Ammodytes personatus are a key forage fish in the North Pacific for many species of salmon, groundfish, seabirds, and marine mammals and have historically been important to predators in relatively warm years. However, extreme declines in the nutritional value of sand lance in Prince William Sound, Alaska, USA, during 2012-2016 indicate that energy transfer from lower trophic levels to predators via sand lance may have been disrupted during the North Pacific marine heatwave in 2015 and 2016. Nutritional value (length, energy density, and whole-body energy) was measured in age-0 and age-1 sand lance collected during July in cool (2012-2013) and increasingly warm (2014-2016) years. The value of age-0 fish was relatively stable, with only minor differences among years for length and whole-body energy. By contrast, the value of age-1 fish significantly declined in 2015, and by 2016 they were 38% shorter and 13% lower in energy density compared to cooler years. This contributed to significant declines in whole-body energy of 44% in 2015 and 89% in 2016 compared to cooler years (2012-2014). The 2015 sand lance cohort experienced little growth or lipid accumulation from July 2015 at age-0 to July 2016 at age-1. This effective disruption of energy flow through pelagic food webs probably contributed to population declines and/or breeding failures observed among several predators in the Gulf of Alaska and suggests that tipping points were reached during the heatwave.

Marine Ecology Progress Series↗
USGS1995

Assimilation of trace elements ingested by the mussel Mytilus edulis: Effects of algal food abundance

Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements ( 110m Ag, 241 Am, 109 Cd, 57 Co, 75 Se and 65 Zn) from ingested diatoms in the mussel Mytilus edulis feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h -1 ). Uniformly radiolabeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotracers in individual mussels was followed for 96 h in a depuration seawater system. Assimilation efficiency (AE) of each element declined with increasing ingestion rate and increased with gut passage time. The importance of extracellular digestion relative to intracellular digestion increased with ingestion activity, which, when coupled with a decline in AE, suggested that extracellular digestion is less efficient in metal absorption. Zn assimilation was most affected by ingestion rate, suggesting that AE may play a role in the physiological regulation of this metal in M. edulis . In an experiment to simulate the effects of an acidic gut, lowered pH (5.5) enhanced the release of elements from intact diatom cells, especially at low particle concentration. These results indicate that both feeding components of the mussel (i.e. gut passage time, digestive partitioning) and metal chemistry (i.e. metal release at lowered pH within the bivalve gut) are responsible for the difference in the assimilation of trace metals at different food quantities observed in mussels.

Marine Ecology Progress Series↗
USGS2019

Confluences function as ecological hotspots: Geomorphic and regional drivers can help identify patterns of fish distribution within a seascape

Quantifying heterogeneity in animal distributions through space and time is a precursor to addressing many important research and management issues. Obtaining these distributional data is especially difficult for mobile organisms that use broader geographic extents. Here, we asked if the merger between 2 research directions—(1) quantifying spatial linkages between fish and geomorphic features (e.g. confluences) and (2) analyzing larger-scale, multi-metric organismal patterns—can provide a broader geographic context for ecological issues that depend on understanding dynamic fish distribution. To address these objectives, we collected data from 59 tagged striped bass Morone saxatilis that were detected by a 26 acoustic receiver array deployed within Plum Island Estuary, MA, USA. We examined these telemetry data using generalized linear mixed models and chi-squared, cluster, and network analyses. Geomorphic site types informed the estuary-wide distribution of striped bass in that tagged fish spent the most time at confluence junctions; however, they did not spend the same amount of time at all junctions. Relative to integrating multiple metrics, number of tagged fish, residence time, and number of movements were not the same across all receivers. When all 3 metrics were considered together, 4 distinct clusters of distributional patterns emerged. Network analyses connected geomorphology and multi-metric seascape patterns. Confluence junctions in the Rowley and Middle regions were the most connected (high centrality) and most used sites (high residence time). Although confluence junctions function as ecological hotspots, researchers and managers will benefit from interpreting geomorphology within a larger geographic context.

Massachusetts↗
USGS2020

Combined influence of intrinsic and environmental factors in shaping productivity in a small pelagic gull, the black-legged kittiwake Rissa tridactyla

While we have a good understanding in many systems of the effects of single variable changes on organisms, we understand far less about how variables act in concert to affect living systems, where interactions among variables can lead to unanticipated results. We used mixed-effect models to evaluate the effects of multiple variables that we expected to play a role in the early reproductive stages of a North Pacific seabird, the black-legged kittiwake Rissa tridactyla, during 1992-2008 using data collected on known-aged individuals. Our work revealed the potential for contrasting stressor effects across successive stages of reproduction. Bird age, timing of egg laying, and winter ENSO conditions best explained individual laying success, such that laying success was greater when parents were older, the average winter ENSO index was positive (as occurs during El Niño episodes), and the median laying date for the colony was earlier. Age and salmon run timing (a proxy for predator presence at the colony) best explained hatching success, such that hatching success was greater when parents were older and when salmon runs were early. Identifying such differential effects of multiple stressors across consecutive reproductive stages can greatly enhance our ability to interpret trends and manage populations in the face of changes currently occurring in living systems.

Marine Ecology Progress Series↗
USGS2020

Variable prey consumption leads to distinct regional differences in Chinook salmon growth during the early marine critical period

Growth during the early marine critical period is positively associated with survival and recruitment for Pacific salmon Oncorhynchus spp., so it is important to understand how certain foraging strategies may bolster growth in estuarine and marine environments. To elucidate how spatiotemporal and demographic differences in diet contribute to growth rate variability, we analyzed stomach contents in tandem with morphometric and hormonal indices of growth for subyearling Chinook salmon O. tshawytscha captured in Puget Sound, Washington, USA. Regional dietary patterns indicated that fish caught in northern Puget Sound ate insects in the estuarine and nearshore habitats, followed by decapod larvae, euphausiids, or forage fish in the offshore zone. In southern Puget Sound, fish ate insects in the estuary but were more likely to eat mysids and other crustaceans in the nearshore zone. In the marine habitats adjacent to the San Juan Islands, subyearlings ate forage fish, and their stomachs were as much as 1.4 to 3 times fuller than salmon captured in other regions. Scale-derived growth rates and insulin-like growth factor-1 levels showed distinct growth advantages for San Juan Islands fish which were strongly associated with the early adoption of piscivory. However, consumption of larger crustaceans such as mysids and euphausiids was also associated with greater relative growth regardless of where individuals were captured. These findings highlight how spatiotemporal differences in prey quantity, prey profitability, and individual foraging strategies result in variable growth rates among salmon populations. Specifically, they emphasize the role of piscivory in promoting early marine growth for out-migrating Chinook salmon.

Washington↗
USGS2020

Growth rates for immature Kemp’s ridley sea turtles from a foraging area in the northern Gulf of Mexico

Examining vital rates helps clarify how environmental characteristics, biological resources and human activities affect population growth. Carapace lengths were gathered for 241 Kemp’s ridley Lepidochelys kempii sea turtles that were marked and recaptured (n = 23) between 2011 and 2019 at a foraging location in northwest Florida, USA. There was a strong correlation between length, width and weight of captured turtles. Mean ± SD size of all captured turtles was 36.6 ± 7.6 cm. Mean recapture interval was 499 ± 475.4 d. Straight-line carapace lengths at initial capture ranged from 20.6 to 53.3 cm. Growth rates from 0.21 to 12.44 cm yr -1 (mean 3.15 ± 2.64 cm) were documented and were greatest for turtles in the 20.0-29.9 cm size class. Growth rates from northwest Florida were slower than those reported from other sites in the Gulf of Mexico. These results indicate that Kemp’s ridleys recruit from oceanic habitat into coastal bays in northwest Florida, where they remain until they reach adulthood. However, some adult-sized turtles may continue to use the nearshore habitat. A gradient in growth rates in the Gulf of Mexico may occur from faster growth in the south to slower growth in the north. Fine-scale variations in resources and environmental conditions may drive regional differences in growth rates, and research on what drives these differences is needed.

Marine Ecology Progress Series↗
USGS2021

Biological correlates of sea urchin recruitment in kelp forest and urchin barren habitats

Shifts between the alternate stable states of sea urchin barren grounds and kelp forests correspond to sea urchin density. In the Aleutian Archipelago, green sea urchins Strongylocentrotus polyacanthus are the dominant herbivores that graze kelp forests. Sea urchin recruitment is an important driver that influences sea urchin density, particularly in the absence of top-down control from a keystone predator such as the sea otter Enhydra lutris . To understand how the biological community may influence patterns of sea urchin recruitment, we compared sea urchin recruit (size ≤20 mm) densities with biomass of other benthic organisms in both barren ground and kelp forest habitats at 9 islands across the Aleutian Archipelago. Patterns of biological community structure between the 2 habitats did not explain patterns of sea urchin recruits; however, the same 10 specific taxa were found to correlate with sea urchin recruits in each habitat. Taxa that showed strong positive correlations included Codium, Constantinea, Schizymenia, and hydrozoans, while strong negative correlations were observed with Pachyarthron and Pugettia . Weak positive correlations were observed with Alcyonidium and ascidiaceans in both habitats, while weak variable relationships were detected with Polysiphonia and Corallina between habitats. The observed species-specific relationships may be due to small sea urchin displacement by larger conspecifics, larval responses to settlement cues, post-settlement survival via biogenic refugia, or potentially predation. These potential species-specific interactions were apparent, regardless of habitat, and it can be inferred that they would be preserved in the presence or absence of keystone predation.

Alaska↗
USGS2021

Regional-scale variability in the movement ecology of marine fishes revealed by an integrative acoustic tracking network

Marine fish movement plays a critical role in ecosystem functioning and is increasingly studied with acoustic telemetry. Traditionally, this research has focused on single species and small spatial scales. However, integrated tracking networks, such as the Integrated Tracking of Aquatic Animals in the Gulf of Mexico (iTAG) network, are building the capacity to monitor multiple species over larger spatial scales. We conducted a synthesis of passive acoustic monitoring data for 29 species (889 transmitters), ranging from large top predators to small consumers, monitored along the west coast of Florida, USA, over 3 yr (2016-2018). Space use was highly variable, with some groups using all monitored areas and others using only the area where they were tagged. The most extensive space use was found for Atlantic tarpon Megalops atlanticus and bull sharks Carcharhinus leucas . Individual detection patterns clustered into 4 groups, ranging from occasionally detected long-distance movers to frequently detected juvenile or adult residents. Synchronized, alongshore, long-distance movements were found for Atlantic tarpon, cobia Rachycentron canadum , and several elasmobranch species. These movements were predominantly northbound in spring and southbound in fall. Detections of top predators were highest in summer, except for nearshore Tampa Bay where the most detections occurred in fall, coinciding with large red drum Sciaenops ocellatus spawning aggregations. We discuss the future of collaborative telemetry research, including current limitations and potential solutions to maximize its impact for understanding movement ecology, conducting ecosystem monitoring, and supporting fisheries management.

Marine Ecology Progress Series↗
USGS1996

Seagrass responses to long-term light reduction by brown tide in upper Laguna Madre, Texas: Distribution and biomass patterns

A brown tide caused by a very dense bloom of an as yet undescribed species of the new class Pelagophyceae was first reported in upper Laguna Madre, Texas, USA, in June 1990 and has been there continuously through December 1995. No change in response to reduced light was evident in the distribution of the seagrass Halodule wrightii along transects sampled before the brown tide in 1988 and resampled after initiation of the brown tide in 1991 and 1992; however, in winter 1993-94 losses were documented over 2.6 km 2 of bottom and by winter 1994-95 the area of vegetation lost had more than tripled to 9.4 km 2 . Changes in biomass presaged the changes in distribution. Decreases in biomass at depths >1.4 m were evident 2 yr before bare areas were detected. Reductions in biomass were more pronounced toward the south, in keeping with a gradient of increasing light attenuation from north to south. Support of a diminishing number of new shoots by reclamation of nutrients and stored reserves from senescing shoots and rhizomes may allow H. wrightii to persist under conditions of insufficient light for periods greatly in excess of the life span of any one shoot. This postulated capability would account for the pattern of diminishing biomass over time where the seagrass persists in deeper areas and the long lag between light reduction and change in distribution where the seagrass succumbed.

Texas↗
USGS2021

Genetic analysis of red lionfish Pterois volitans from Florida, USA, leads to alternative North Atlantic introduction scenarios

The red lionfish Pterois volitans is a successful invasive predator across the western North Atlantic, Caribbean, and Gulf of Mexico. The southeast coast of Florida (USA) has been identified as the original introduction location, but genetic analyses including Florida lionfish have yet to investigate introduction scenarios. Here, we assessed the potential lionfish invasion pathways using 1795 sequences from previously published mitochondrial D-loop sequences (n = 1558) and new samples (n = 237) from 6 locations: The Bahamas, Florida Keys, northwest Florida, North Carolina, Panamá, and southeast Florida. None of the assessed Florida lionfish (n = 394) contained the H05-H09 D-loop haplotypes found in The Bahamas, North Carolina, and Bermuda (the Northern Region), indicating that Florida was not the source for these haplotypes. Assessing the mitochondrial population structure, the Florida east coast lionfish grouped with the Caribbean/Gulf of Mexico, as opposed to the Northern Region. To further explore connectivity and invasion pathways, 14 nuclear microsatellite loci were multiplexed on lionfish collected from 15 locations (n = 394). As found in other nuclear lionfish studies, the analyses identified a lack of population structure likely due to founding effects and/or inbreeding in aquaculture brood stocks. Together, the significant haplotype differences and H01-H04 haplotypes refute Florida as the sole source of red lionfish introduction. The results of this study support alternative invasion scenarios, in which Florida was colonized as a secondary introduction site or by individuals from the Northern Region. Understanding invasive species’ population boundaries and dispersal patterns informs local control efforts and management planning for future invasive species introductions.

Florida↗