Suca
Justin J.
Suca
Justin J.
No Thumbnail Available
Search Results
Now showing
1 - 13 of 13
-
ArticleLarval transport pathways from three prominent sand lance habitats in the Gulf of Maine(Wiley, 2022-03-15) Suca, Justin J. ; Ji, Rubao ; Baumann, Hannes ; Pham, Kent ; Silva, Tammy L. ; Wiley, David N. ; Feng, Zhixuan ; Llopiz, Joel K.Northern sand lance (Ammodytes dubius) are among the most critically important forage fish throughout the Northeast US shelf. Despite their ecological importance, little is known about the larval transport of this species. Here, we use otolith microstructure analysis to estimate hatch and settlement dates of sand lance and then use these measurements to parametrize particle tracking experiments to assess the source–sink dynamics of three prominent sand lance habitats in the Gulf of Maine: Stellwagen Bank, the Great South Channel, and Georges Bank. Our results indicate the pelagic larval duration of northern sand lance lasts about 2 months (range: 50–84 days) and exhibit a broad range of hatch and settlement dates. Forward and backward particle tracking experiments show substantial interannual variability, yet suggest transport generally follows the north to south circulation in the Gulf of Maine region. We find that Stellwagen Bank is a major source of larvae for the Great South Channel, while the Great South Channel primarily serves as a sink for larvae from Stellwagen Bank and Georges Bank. Retention is likely the primary source of larvae on Georges Bank. Retention within both Georges Bank and Stellwagen Bank varies interannually in response to changes in local wind events, while the Great South Channel only exhibited notable retention in a single year. Collectively, these results provide a framework to assess population connectivity among these sand lance habitats, which informs the species' recruitment dynamics and impacts its vulnerability to exploitation.
-
PreprintFeeding dynamics of Northwest Atlantic small pelagic fishes( 2018-04) Suca, Justin J. ; Pringle, Julie W. ; Knorek, Zofia R. ; Hamilton, Sara L. ; Richardson, David E. ; Llopiz, Joel K.Small pelagic fishes represent a critical link between zooplankton and large predators. Yet, the taxonomic resolution of the diets of these important fishes is often limited, especially in the Northwest Atlantic. We examined the diets, along with stable isotope signatures, of five dominant small pelagic species of the Northeast US continental shelf ecosystem (Atlantic mackerel Scomber scombrus, Atlantic herring Clupea harengus, alewife Alosa pseudoharengus, blueback herring Alosa aestivalis, and Atlantic butterfish Peprilus triacanthus). Diet analyses revealed strong seasonal differences in most species. Small pelagic fishes predominantly consumed Calanus copepods, small copepod genera (Pseudocalanus/Paracalanus/Clausocalanus), and Centropages copepods in the spring, with appendicularians also important by number for most species. Krill, primarily Meganyctiphanes norvegica, and hyperiid amphipods of the genera Hyperia and Parathemisto were common in the stomach contents of four of the five species in the fall, with hyperiids common in the stomach contents of butterfish in both seasons and krill common in the stomach contents of alewife in both seasons. Depth and region were also found to be sources of variability in the diets of Atlantic mackerel, Atlantic herring, and alewife (region but not depth) with krill being more often in the diet of alewife in more northerly locations, primarily the Gulf of Maine. Stable isotope data corroborate the seasonal differences in diet but overlap of isotopic niche space contrasts that of dietary overlap, highlighting the differences in the two methods. Overall, the seasonal variability and consumer-specific diets of small pelagic fishes are important for understanding how changes in the zooplankton community could influence higher trophic levels.
-
ArticleEnvironmental drivers and trends in forage fish occupancy of the Northeast US shelf(Oxford University Press, 2021-11-02) Suca, Justin J. ; Deroba, Jonathan J. ; Richardson, David E. ; Ji, Rubao ; Llopiz, Joel K.The Northeast US shelf ecosystem is undergoing unprecedented changes due to long-term warming trends and shifts in regional hydrography leading to changes in community composition. However, it remains uncertain how shelf occupancy by the region's dominant, offshore small pelagic fishes, also known as forage fishes, has changed throughout the late 20th and early 21st centuries. Here, we use species distribution models to estimate the change in shelf occupancy, mean weighted latitude, and mean weighted depth of six forage fishes on the Northeast US shelf, and whether those trends were linked to coincident hydrographic conditions. Our results suggest that observed shelf occupancy is increasing or unchanging for most species in both spring and fall, linked both to gear shifts and increasing bottom temperature and salinity. Exceptions include decreases to observed shelf occupancy by sand lance and decreases to Atlantic herring's inferred habitat suitability in the fall. Our work shows that changes in shelf occupancy and inferred habitat suitability have varying coherence, indicating complex mechanisms behind observed shelf occupancy for many species. Future work and management can use these results to better isolate the aspects of forage fish life histories that are important for determining their occupancy of the Northeast US shelf.
-
ArticleSensitivity of sand lance to shifting prey and hydrography indicates forthcoming change to the northeast US shelf forage fish complex(Oxford University Press, 2021-01-26) Suca, Justin J. ; Wiley, David N. ; Silva, Tammy L. ; Robuck, Anna R. ; Richardson, David E. ; Glancy, Sarah G. ; Clancey, Emily ; Giandonato, Teresa ; Solow, Andrew R. ; Thompson, Michael A. ; Hong, Peter ; Baumann, Hannes ; Kaufman, Les ; Llopiz, Joel K.Northern sand lance (Ammodytes dubius) and Atlantic herring (Clupea harengus) represent the dominant lipid-rich forage fish species throughout the Northeast US shelf and are critical prey for numerous top predators. However, unlike Atlantic herring, there is little research on sand lance or information about drivers of their abundance. We use intra-annual measurements of sand lance diet, growth, and condition to explain annual variability in sand lance abundance on the Northeast US Shelf. Our observations indicate that northern sand lance feed, grow, and accumulate lipids in the late winter through summer, predominantly consuming the copepod Calanus finmarchicus. Sand lance then cease feeding, utilize lipids, and begin gonad development in the fall. We show that the abundance of C. finmarchicus influences sand lance parental condition and recruitment. Atlantic herring can mute this effect through intra-guild predation. Hydrography further impacts sand lance abundance as increases in warm slope water decrease overwinter survival of reproductive adults. The predicted changes to these drivers indicate that sand lance will no longer be able to fill the role of lipid-rich forage during times of low Atlantic herring abundance—changing the Northeast US shelf forage fish complex by the end of the century.
-
PreprintTrophic ecology of barrelfish (Hyperoglyphe perciformis) in oceanic waters of southeast Florida( 2017-09) Suca, Justin J. ; Llopiz, Joel K.Deep-water demersal fishes represent an understudied but ecologically important group of organisms. Select species of demersal fishes rely on pelagic prey items, representing a direct transport of surface carbon to greater depths. Barrelfish Hyperoglyphe perciformis (Mitchell, 1818), which inhabit deep slope waters, are a species that has been suggested to fill this role, as congeners consume primarily pelagic gelatinous zooplankton; however, there is a dearth of information on the trophic ecology of barrelfish. Stomach content and stable isotope analyses were conducted on barrelfish caught by recreational fishers off Miami, Florida to improve our understanding of the feeding of this species. Pyrosoma atlanticum (Péron, 1804), a pelagic, vertically migrating tunicate, represented 89% of the barrelfish diet by weight. Mesopelagic fish and shrimp contributed much smaller proportions. Standard ellipse areas corrected for sample size (SEAc) showed a substantially smaller isotopic niche width for barrelfish (0.606 ‰2) than dolphinfish (2.16 ‰2), king mackerel (3.04 ‰2), or wahoo (1.97 ‰2). Coupled with dependence on a singular prey item, the low SEAc of barrelfish suggests they occupy a limited trophic niche space. Overlap of barrelfish SEAc with dolphinfish (99.5% overlap) and king mackerel (100% overlap) indicate that the carbon sources as well as the number of trophic steps for barrelfish are similar to king mackerel and dolphinfish and are linked to surface waters. This trophic linkage suggests that barrelfish may play a role in carbon export and further study into their behavior and daily consumption rates is warranted for quantifying this role.
-
ArticleHigh collocation of sand lance and protected top predators: implications for conservation and management(Wiley Open Access, 2020-10-06) Silva, Tammy L. ; Wiley, David N. ; Thompson, Michael A. ; Hong, Peter ; Kaufman, Les ; Suca, Justin J. ; Llopiz, Joel K. ; Baumann, Hannes ; Fay, GavinSpatial relationships between predators and prey provide critical information for understanding and predicting climate‐induced shifts in ecosystem dynamics and mitigating human impacts. We used Stellwagen Bank National Marine Sanctuary as a case study to investigate spatial overlap among sand lance (Ammodytes dubius), a key forage fish species, and two protected predators: humpback whales (Megaptera novaeangliae) and great shearwaters (Ardenna gravis). We conducted 6 years (2013–2018) of standardized surveys and quantified spatial overlap using the global index of collocation. Results showed strong, consistent collocation among species across seasons and years, suggesting that humpback whales and great shearwater distributions are tightly linked to sand lance. We propose that identifying sand lance habitats may indicate areas where humpbacks and shearwaters aggregate and are particularly vulnerable to human activities. Understanding how sand lance influence predator distributions can inform species protection and sanctuary management under present and future scenarios.
-
ArticleSoundscapes influence the settlement of the common caribbean coral porites astreoides irrespective of light conditions(Royal Society, 2018-12-12) Lillis, Ashlee ; Apprill, Amy ; Suca, Justin J. ; Becker, Cynthia ; Llopiz, Joel K. ; Mooney, T. AranThe settlement of reef-building corals is critical to the survival and recovery of reefs. Recent evidence indicates that coral larvae orient towards reef sound, yet the components of the acoustic environment that may attract coral larvae and induce settlement are unknown. Here we investigated the effects of ambient soundscapes on settlement of Porites astreoides coral larvae using in situ chambers on reefs differing in habitat quality (coral and fish abundance). Mean larval settlement was twice as high in an acoustic environment with high levels of low-frequency sounds, typical of a high-quality, healthy reef; this result was observed in both natural light and dark treatments. Overall, the enhancement of coral settlement by soundscapes typical of healthy reefs suggests a positive feedback where soundscape properties of reefs with elevated coral and fish abundance may facilitate coral recruitment.
-
PreprintMultiscale spatio-temporal patterns of boat noise on U.S. Virgin Island coral reefs( 2018-09) Dinh, Jason P. ; Suca, Justin J. ; Lillis, Ashlee ; Apprill, Amy ; Llopiz, Joel K. ; Mooney, T. AranSound-sensitive organisms are abundant on coral reefs. Accordingly, experiments suggest that boat noise could elicit adverse effects on coral reef organisms. Yet, there are few data quantifying boat noise prevalence on coral reefs. We use long-term passive acoustic recordings at nine coral reefs and one sandy comparison site in a marine protected area to quantify spatio-temporal variation in boat noise and its effect on the soundscape. Boat noise was most common at reefs with high coral cover and fish density, and temporal patterns reflected patterns of human activity. Boat noise significantly increased low-frequency sound levels at the monitored sites. With boat noise present, the peak frequencies of the natural soundscape shifted from higher frequencies to the lower frequencies frequently used in fish communication. Taken together, the spectral overlap between boat noise and fish communication and the elevated boat detections on reefs with biological densities raises concern for coral reef organisms.
-
ArticleThe role of sand lances (Ammodytes sp.) in the Northwest Atlantic ecosystem: a synthesis of current knowledge with implications for conservation and management(Wiley, 2020-03-20) Staudinger, Michelle D. ; Goyert, Holly ; Suca, Justin J. ; Coleman, Kaycee ; Welch, Linda ; Llopiz, Joel K. ; Wiley, David N. ; Altman, Irit ; Applegate, Andew ; Auster, Peter J. ; Baumann, Hannes ; Beaty, Julia ; Boelke, Deirdre ; Kaufman, Les ; Loring, Pam ; Moxley, Jerry ; Paton, Suzanne ; Powers, Kevin D. ; Richardson, David E. ; Robbins, Jooke ; Runge, Jeffrey A. ; Smith, Brian ; Spiegel, Caleb ; Steinmetz, HalleyThe American sand lance (Ammodytes americanus, Ammodytidae) and the Northern sand lance (A. dubius, Ammodytidae) are small forage fishes that play an important functional role in the Northwest Atlantic Ocean (NWA). The NWA is a highly dynamic ecosystem currently facing increased risks from climate change, fishing and energy development. We need a better understanding of the biology, population dynamics and ecosystem role of Ammodytes to inform relevant management, climate adaptation and conservation efforts. To meet this need, we synthesized available data on the (a) life history, behaviour and distribution; (b) trophic ecology; (c) threats and vulnerabilities; and (d) ecosystem services role of Ammodytes in the NWA. Overall, 72 regional predators including 45 species of fishes, two squids, 16 seabirds and nine marine mammals were found to consume Ammodytes. Priority research needs identified during this effort include basic information on the patterns and drivers in abundance and distribution of Ammodytes, improved assessments of reproductive biology schedules and investigations of regional sensitivity and resilience to climate change, fishing and habitat disturbance. Food web studies are also needed to evaluate trophic linkages and to assess the consequences of inconsistent zooplankton prey and predator fields on energy flow within the NWA ecosystem. Synthesis results represent the first comprehensive assessment of Ammodytes in the NWA and are intended to inform new research and support regional ecosystem‐based management approaches.
-
ArticleMicrobial and nutrient dynamics in mangrove, reef, and seagrass waters over tidal and diurnal time scales(Inter Research, 2020-10-08) Becker, Cynthia ; Weber, Laura ; Suca, Justin J. ; Llopiz, Joel K. ; Mooney, T. Aran ; Apprill, AmyIn coral reefs and adjacent seagrass meadow and mangrove environments, short temporal scales (i.e. tidal, diurnal) may have important influences on ecosystem processes and community structure, but these scales are rarely investigated. This study examines how tidal and diurnal forcings influence pelagic microorganisms and nutrient dynamics in 3 important and adjacent coastal biomes: mangroves, coral reefs, and seagrass meadows. We sampled for microbial (Bacteria and Archaea) community composition, cell abundances and environmental parameters at 9 coastal sites on St. John, US Virgin Islands that spanned 4 km in distance (4 coral reefs, 2 seagrass meadows and 3 mangrove locations within 2 larger bays). Eight samplings occurred over a 48 h period, capturing day and night microbial dynamics over 2 tidal cycles. The seagrass and reef biomes exhibited relatively consistent environmental conditions and microbial community structure but were dominated by shifts in picocyanobacterial abundances that were most likely attributed to diel dynamics. In contrast, mangrove ecosystems exhibited substantial daily shifts in environmental parameters, heterotrophic cell abundances and microbial community structure that were consistent with the tidal cycle. Differential abundance analysis of mangrove-associated microorganisms revealed enrichment of pelagic oligotrophic taxa during high tide and enrichment of putative sediment-associated microbes during low tide. Our study underpins the importance of tidal and diurnal time scales in structuring coastal microbial and nutrient dynamics, with diel and tidal cycles contributing to a highly dynamic microbial environment in mangroves, and time of day likely contributing to microbial dynamics in seagrass and reef biomes.
-
ArticleBirds of a feather eat plastic together: high levels of plastic ingestion in Great Shearwater adults and juveniles across their annual migratory cycle(Frontiers Media, 2022-01-05) Robuck, Anna R. ; Hudak, Christine A. ; Agvent, Lindsay ; Emery, Gwenyth ; Ryan, Peter G. ; Perold, Vonica ; Powers, Kevin D. ; Pedersen, Johanna ; Thompson, Michael A. ; Suca, Justin J. ; Moore, Michael J. ; Harms, Craig A. ; Bugoni, Leandro ; Shield, Gina ; Glass, Trevor ; Wiley, David N. ; Lohmann, RainerLimited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters (Ardenna gravis) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance (Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems.
-
ThesisEnvironmental drivers of the abundance and distribution of forage fishes on the Northeast US shelf, with a particular emphasis on northern sand lance(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2021-09) Suca, Justin J.Small pelagic fishes, also termed forage fishes, represent a critical link between secondary production and myriad top predators in marine ecosystems, including the Northeast US shelf. In this dissertation, I analyze the drivers of forage fish distribution throughout the Northeast US shelf and the drivers of the abundance of the ecologically important northern sand lance. Chapter 2 examines the basic ecology of northern sand lance and uses these insights to identify mechanistic drivers of their abundance. I then explore different scenarios of these drivers to project sand lance abundance through the end of the 21st century, which appears precarious for adult sand lance unless current trajectories change. Chapter 3 analyzes the environmental drivers of the distribution of the six dominant, offshore forage fish species (northern sand lance, Atlantic herring, alewife, blueback herring, Atlantic mackerel, and Atlantic butterfish) on the Northeast US shelf to elucidate the role of environmental covariates in shelf occupancy by these taxa. The results of this chapter indicate shelf occupancy of butterfish and Atlantic mackerel are increasing through time while occupancy of sand lance is decreasing with time. The occurrence of most of these species is also moving deeper and northward with time. Chapter 4 assesses the source-sink dynamics of three sand lance hotspots through Lagrangian particle tracking models simulating larval sand lance transport. Connectivity varies among these hotspots with Georges Bank and Stellwagen Bank having notable retention while the Great South Channel relies on larvae from other hotspots. Retention on Stellwagen Bank and Georges Bank are linked to strong wind events during the larval period of sand lance. Collectively, this dissertation improves our understanding of the dynamics driving variability in the Northeast US shelf forage fish complex, particularly for northern sand lance.
-
PreprintCharacterizing larval swordfish habitat in the western tropical North Atlantic( 2017-09) Suca, Justin J. ; Rasmuson, Leif K. ; Malca, Estrella ; Gerard, Trika ; Lamkin, John T.Swordfish Xiphias gladius (Linnaeus, 1758) are a circumglobal pelagic fish targeted by multiple lucrative fisheries. Determining the distribution of swordfish larvae is important for indicating reproductive activity and understanding the early life history of swordfish. We identify and characterize larval swordfish distributions during peak swordfish spawning throughout the Gulf of Mexico and western Caribbean Sea with generalized additive models (GAMs) using catches of swordfish larvae during ichthyoplankton surveys in April and May of 2010, 2011, and 2012. The best fit GAM, as determined by stepwise, backward Akaike Information Criterion selection, included both physiochemical (temperature at 5 m, sea surface height anomaly (SSHA), eddy kinetic energy (EKE)), temporal (lunar illumination, hour of sampling) and spatial (location) variables, while near-surface chlorophyll a concentration residuals remained as a random effect. The highest probability of larval swordfish catch occurred at sub-surface temperatures, SSHA, and EKE values indicative of boundary currents. Standard lengths of larvae were larger further downstream in the boundary currents, despite high variability in length with location due to multiple spawning locations of swordfish near these currents. Probability of larval swordfish catch also peaked during the crescent and gibbous moons, indicating a lunar periodicity to swordfish spawning. These results suggest that swordfish may spawn during select moon phases near boundary currents that transport their larvae to larval and juvenile habitat including the northern Gulf of Mexico and coastal waters of the southeast United States.