Consequences of plume encounter on larval fish growth and condition in the Gulf of Mexico

2020 ◽  
Vol 650 ◽  
pp. 63-80 ◽  
Author(s):  
KE Axler ◽  
S Sponaugle ◽  
F Hernandez ◽  
C Culpepper ◽  
RK Cowen
Keyword(s):  
Gulf Of Mexico ◽  
Continental Shelf ◽  
Prey Capture ◽  
Larval Fish ◽  
Fish Larvae ◽  
Fish Growth ◽  
Frequency Distributions ◽  
Larval Fishes ◽  
River Estuarine ◽  
Anchoa Hepsetus

Freshwater input into nearshore continental shelf waters from coastal river-estuarine plumes can greatly alter the physical and trophic environments experienced by fish larvae. However, the biological consequences of plume encounter on larval fish survival remain equivocal, largely due to the extreme variability of these systems but also because traditional sampling techniques alone are too coarse to effectively characterize the dynamic biophysical environment at spatiotemporal scales relevant to individual larvae. Using a multidimensional approach, we simultaneously collected in situ imagery and net samples of larval fishes and zooplankton from the Mobile Bay plume (Alabama, USA) and ambient continental shelf waters during a high discharge event (8-11 April 2016). We measured the effects of plume encounter on growth and condition of larval striped anchovy Anchoa hepsetus and sand seatrout Cynoscion arenarius, 2 prominent nearshore species in the northern Gulf of Mexico. Size-frequency distributions of both species indicated that larger individuals were present in shelf waters but absent from plume waters. Otolith microstructure analysis revealed that recent growth of both focal species was significantly lower for plume-collected larvae during the last few days prior to capture. Furthermore, plume larvae were in poorer morphometric condition (skinnier at length) than their shelf counterparts, despite the fact that there were higher concentrations of zooplankton prey in plume water masses. Taken together, these results suggest that elevated prey concentrations do not necessarily translate to higher growth and condition. High turbulence and turbidity within the plume may physically inhibit the prey capture ability and feeding success of fish larvae.

scholarly journals Hydrodynamic regime drives flow reversals in suction feeding larval fishes during early ontogeny

2019 ◽  
Author(s):  
Krishnamoorthy Krishnan ◽  
Asif Shahriar Nafi ◽  
Roi Gurka ◽  
Roi Holzman
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Prey Capture ◽  
Sparus Aurata ◽  
Larval Fish ◽  
Fish Larvae ◽  
Numerical Models ◽  
Hydrodynamic Regime ◽  
Suction Feeding ◽  
Larval Fishes

AbstractFish larvae are the smallest self-sustaining vertebrates. As such, they face multiple challenge that stem from their minute size, and from the hydrodynamic regime in which they dwell. This regime of intermediate Reynolds numbers (Re) was shown to affect the swimming of larval fish and impede their ability to capture prey. Numerical simulations indicate that the flow fields external to the mouth in younger larvae result in shallower spatial gradients, limiting the force exerted on the prey. However, observations on feeding larvae suggest that failures in prey capture can also occur during prey transport, although the mechanism causing these failures is unclear. We combine high-speed videography and numerical simulations to investigate the hydrodynamic mechanisms that impede prey transport in larval fishes. Detailed kinematics of the expanding mouth during prey capture by larval Sparus aurata were used to parameterize age-specific numerical models of the flows inside the mouth. These models reveal that, for small larvae that slowly expand their mouth, not all the fluid that enters the mouth cavity is expelled through the gills, resulting in flow reversal at the mouth orifice. This efflux at the mouth orifice was highest in the younger ages, but was also high (>8%) in slow strikes produced by larger fish. Our modeling explains the observations of “in-and-out” events in larval fish, where prey enters the mouth but is not swallowed. It further highlights the importance of prey transport as an integral part in determining suction feeding success.

scholarly journals Once upon a larva: revisiting the relationship between feeding success and growth in fish larvae

2014 ◽  
Vol 72 (2) ◽  
pp. 359-373 ◽  
Author(s):  
Pierre Pepin ◽  
Dominique Robert ◽  
Caroline Bouchard ◽  
John F. Dower ◽  
Marianne Falardeau ◽  
...  
Keyword(s):  
Growth Rates ◽  
Larval Fish ◽  
Fish Larvae ◽  
Fish Growth ◽  
Individual Growth ◽  
Growth Time ◽  
Feeding Rates ◽  
Average Growth ◽  
Fast Growing ◽  
Feeding Success

Abstract Variations in larval fish growth rates are largely the result of variability in biotic and abiotic characteristics of the feeding environment experienced by each individual. An assessment of an individual's overall feeding success (i.e. accumulation of utilizable organic matter) can best be achieved at the time of capture when the relationships among environment, short-term feeding success as defined by gut content and long-term feeding success as defined by accumulated growth can be contrasted. Here, we investigated the relationships between average growth, feeding success, and variability in individual growth and feeding rates across a range of taxa based on a synthesis of studies in which stomach content and otolith growth were measured in the same individuals. Instantaneous measures of feeding success were highly variable and demonstrated a positive yet somewhat limited association with growth rates across all taxa. The strength of the feeding-growth relationships among taxa, and cohorts within taxa, was reflected in the autocorrelation of individual growth rates, suggesting that stable growth was achieved through consistent feeding success. However, when viewed at the individual level, faster growth was achieved in individuals with more variable growth rates, and by inference more variable past feeding success. The dichotomy in these underlying relationships may point to the importance of stochastic events in the development of exceptional individuals in a population, and may be linked to how surplus energy is allocated to individual growth rates. The positive correlation found between feeding success and growth in all taxa is consistent with the growth-survival paradigm for the larval stage of fish. However, both the correlation between feeding success and growth and the serial correlation of growth time-series was greatest in fast-growing species, suggesting that the potential for an early “critical period” regulating survival varies among species, reaching a maximum in fast-growing fish.

Limnology of rearing ponds for Australian fish larvae: Relationships among water quality, phytoplankton, zooplankton, and the growth of larval fish

1993 ◽  
Vol 44 (4) ◽  
pp. 537 ◽  
Author(s):  
DA Culver ◽  
MC Geddes
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
N:P Ratio ◽  
Fish Growth ◽  
Phytoplankton Blooms ◽  
Chironomid Larvae ◽  
Cyanobacterium Anabaena ◽  
Australian Fish ◽  
Zooplankton Succession ◽  
Zooplankton Communities

Fertilization of earthen ponds used to rear the larvae of golden perch, Macquaria ambigua, and silver perch, Bidyanus bidyanus, resulted in phytoplankton blooms dominated by the cyanobacterium Anabaena possibly because of a low N:P ratio. There was a zooplankton succession of rotifers (mostly Brachionus), Moina, Boeckella and Mesocyclops, and then Daphnia. An increase in Daphnia correlated with a decline in Anabaena, suggesting grazing on that cyanobacterium. Golden perch larvae included copepods in their diet whereas silver perch did not, and this was reflected in lower Boeckella numbers in the golden perch ponds. There was sufficient zooplankton forage, supplemented by chironomid larvae in the later stages of the rearing ponds, for fish growth. The limnological conditions and zooplankton communities in these ponds provide a model for evaluating nursery grounds for these fish.

Larval fishes of a Middle Atlantic Bight estuary: assemblage structure and temporal stability

1999 ◽  
Vol 56 (2) ◽  
pp. 222-230 ◽  
Author(s):  
David A Witting ◽  
Kenneth W Able ◽  
Michael P Fahay
Keyword(s):  
Continental Shelf ◽  
Dominant Species ◽  
Fish Assemblages ◽  
Larval Fish ◽  
Temporal Stability ◽  
Temperature Cycle ◽  
Sargasso Sea ◽  
Larval Fishes ◽  
Middle Atlantic ◽  
Lower Temperature

We collected weekly, quantitative ichthyoplankton samples over 6 years (1989-1994, 1309 samples) to identify temporal scales of variability in the abundance and occurrence of larval fish assemblages near Little Egg Inlet in southern New Jersey, U.S.A. We collected species that spawn in the estuary (30%), both the estuary and continental shelf (35%), continental shelf (25%), and the Sargasso Sea (10%). The following analyses suggest an annually repeated seasonal progression of species assemblages: (i) the rank abundance of the 20 dominant species did not change significantly from year to year, (ii) variation in the density of the dominant species was primarily explained by intraannual rather than interannual variation, and (iii) multivariate analysis of the assemblage matrix identified five seasonal assemblages that occurred during all six years. We found that the timing and duration of each of these seasonal groups were correlated with two characteristics of the annual temperature cycle, magnitude (higher or lower temperature) and trajectory (increasing vs decreasing temperature). We suggest that the repeated occurrence of larval fish assemblages in temperate estuaries along the U.S. coast may, in part, be driven by local environmental processes.

Evaluation of in situ Enclosures for Larval Fish Studies

1987 ◽  
Vol 44 (1) ◽  
pp. 54-65 ◽  
Author(s):  
Yves de Lafontaine ◽  
William C. Leggett
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Low Cost ◽  
Experimental Studies ◽  
Size Composition ◽  
Surrounding Water ◽  
Larval Fishes ◽  
Plastic Bags ◽  
Capelin Mallotus Villosus

Two in situ enclosure designs intended for use in larval fish studies were evaluated for their capability to reproduce and track the physical properties of the surrounding water and to maintain the behavioral characteristics of enclosed organisms. The enclosures, which were constructed of porous material, allowed near instantaneous response to natural variations in temperature, salinity, and dissolved oxygen at all depths. Phytoplankton biomass inside the enclosures was less variable than that observed outside and its size composition was related to the porosity of the material used. Particle sinking rates inside the enclosures were much lower than those previously reported for plastic bags, suggesting a higher degree of turbulence in our enclosures. Newly hatched larval capelin (Mallotus villosus) and Zooplankton stocked into the enclosures exhibited diel migration of amplitude similar to that observed in the field. Zooplankton were more homogeneously distributed than fish larvae although heterogeneity decreased at night for both taxa. Low cost, ease of handling, environmental reproducibility, and quality of replication provided by the enclosures make them particularly appropriate for replicated experimental studies of the interactions between larval fishes, their predators, and prey.

scholarly journals Habitat use and the effect of shrimp trawling on fish and invertebrate communities over the northern Gulf of Mexico continental shelf

2008 ◽  
Vol 65 (9) ◽  
pp. 1610-1619 ◽  
Author(s):  
R. J. David Wells ◽  
James H. Cowan ◽  
William F. Patterson
Keyword(s):  
Community Structure ◽  
Gulf Of Mexico ◽  
Habitat Use ◽  
Continental Shelf ◽  
Habitat Characteristics ◽  
Fish Community Structure ◽  
Remotely Operated Vehicle ◽  
Frequency Distributions ◽  
Invertebrate Communities ◽  
Northern Gulf Of Mexico

Abstract Wells, R. J. D., James H. Cowan Jr, and William F. Patterson III. 2008. Habitat use and the effect of shrimp trawling on fish and invertebrate communities over the northern Gulf of Mexico continental shelf. – ICES Journal of Marine Science, 65: 1610–1619. The goals of this study were to characterize habitat-specific fish and invertebrate community structure over sand, shell-rubble, and natural reef substrata, and to assess the effects of trawling on the sand and shell-rubble habitats and their associated communities during quarterly trawl surveys over a 2-year period. Fish and invertebrate communities differed significantly among habitat types [analysis of similarities (ANOSIM); Global R = 0.436, p < 0.001), and with respect to trawling exposure (ANOSIM; Global R = 0.128, p < 0.001). Habitat characteristics were quantified from video transects sampled with a remotely operated vehicle, and included percentage coverage of tubeworms, bryozoans, anemones, corals, and algae, significantly affecting fish community structure. Diversity indices differed among habitats, with the highest Shannon diversity (H′) and Pielou's evenness (J′) over shell-rubble, specifically non-trawled shell-rubble. In addition, higher values of H′ and J′ were found over trawled sand relative to non-trawled sand habitats. Length frequency distributions of several abundant fish species showed truncated size distributions over trawled and non-trawled habitats and were both habitat- and species-specific. The study describes habitat-specific differences in community structure, highlighting the differences between trawled and non-trawled areas on the northern Gulf of Mexico continental shelf.

scholarly journals Assemblage Structure of Larval Fishes in Epipelagic and Mesopelagic Waters of the Northern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Verena H. Wang ◽  
Carley R. Zapfe ◽  
Frank J. Hernandez
Keyword(s):  
Gulf Of Mexico ◽  
Environmental Conditions ◽  
Early Life ◽  
Fish Assemblages ◽  
Larval Fish ◽  
Critical Role ◽  
Life Stages ◽  
Early Life Stages ◽  
Northern Gulf Of Mexico ◽  
Larval Fishes

The early life stages of fishes play a critical role in pelagic food webs and oceanic carbon cycling, yet little is known about the taxonomic composition and distribution of larval fishes in the northern Gulf of Mexico (GOM) below the epipelagic (&lt;200 m). Here, we provide the first large-scale characterization of larval fish assemblages in the GOM across epipelagic, mesopelagic, and bathypelagic regions (0–1,500 m), using samples collected during the Natural Resource Damage Assessment conducted following the Deepwater Horizon oil spill (DWHOS). These data contain &gt; 130,000 ichthyoplankton specimens from depth-discrete plankton samples collected across 48 stations in the GOM during six cruises conducted in 2010 and 2011. We examined indices of abundance and diversity, and used a multivariate regression tree approach to model the relationship between larval fish assemblages and environmental conditions. The total abundance of larval fish followed a generally decreasing trend with increasing depth, and family-level richness and diversity were significantly higher in the epipelagic than mesopelagic and bathypelagic regions. Fourteen distinct assemblage groups were identified within the epipelagic, with depth, surface salinity, and season contributing to the major branches separating groups. Within the mesopelagic, seven distinct assemblage groups were identified and were largely explained by variation in depth, season, and surface temperature. Bathypelagic assemblages were poorly described by environmental conditions. The most common epipelagic assemblage groups were widely distributed across the GOM, as were all mesopelagic assemblage groups, suggesting limited horizontal structuring of GOM larval fishes. Of the mesopelagic-associated fish taxa, four dominant families (Myctophidae, Gonostomatidae, Sternoptychidae, Phosichthyidae) comprised the majority of the catch in both the epipelagic (63%) and combined mesopelagic and bathypelagic (97%) regions. Dufrêne-Legendre indicator analysis confirmed that these dominant families were characteristic of epipelagic and mesopelagic assemblages; the larvae of less common mesopelagic-associated families largely identified with epipelagic assemblage groups. A lack of baseline data about the distribution patterns of early life stages of mesopelagic fishes in the GOM was apparent following the DWHOS, and these findings provide a valuable reference point in the face of future ecosystem stressors.

Isotopic characterization of lifetime movement by two demersal fishes from the northeastern Gulf of Mexico

2021 ◽  
Vol 657 ◽  
pp. 161-172
Author(s):  
JL Vecchio ◽  
JL Ostroff ◽  
EB Peebles
Keyword(s):  
Gulf Of Mexico ◽  
Continental Shelf ◽  
Life Histories ◽  
Linear Mixed Model ◽  
Trophic Position ◽  
Eye Lens ◽  
Outer Continental Shelf ◽  
Red Grouper ◽  
Lens Diameter ◽  
Isotopic Characterization

An understanding of lifetime trophic changes and ontogenetic habitat shifts is essential to the preservation of marine fish species. We used carbon and nitrogen stable isotope values (δ13C and δ15N) recorded within the laminar structure of fish eye lenses, reflecting both diet and location over time, to compare the lifetime trends of 2 demersal mesopredators. Tilefish Lopholatilus chamaeleonticeps inhabit burrows on the outer continental shelf, which results in exceptional site fidelity. Red grouper Epinephelus morio are spawned on the middle to outer continental shelf, move to the inner shelf for the juvenile period, and return offshore upon sexual maturity. Both species inhabit the eastern Gulf of Mexico, a region with a distinctive offshore-inshore gradient in background δ13C values. Within individual tilefish (n = 36), sequences of δ13C values and δ15N values had strong, positive correlations with eye-lens diameter, and strong correlations between the 2 isotopes (mean Spearman r = 0.86), reflecting an increase in trophic position with growth and little lifetime movement. In red grouper (n = 30), δ15N values positively correlated with eye-lens diameter, but correlations between δ15N and δ13C were weak (mean Spearman r = 0.29), suggesting cross-shelf ontogenetic movements. Linear mixed model results indicated strong relationships between δ15N and δ13C values in tilefish eye lenses but no convergence in the red grouper model. Collectively, these results are consistent with previously established differences in the life histories of the 2 species, demonstrating the potential utility of eye-lens isotope records, particularly for investigating the life histories of lesser-known species.

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