scholarly journals Larval Fish Assemblage Structure at Coastal Fronts and the Influence of Environmental Variability

2021 ◽  
Vol 9 ◽  
Author(s):  
Paula Pattrick ◽  
Nicolas Weidberg ◽  
Wayne S. Goschen ◽  
Jennifer M. Jackson ◽  
Christopher D. McQuaid ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Environmental Variability ◽  
Larval Fish ◽  
Fish Larvae ◽  
Fish Assemblage Structure ◽  
Larval Connectivity ◽  
Coastal Species ◽  
Pelagic Eggs ◽  
Frontal Systems ◽  
Abundance And Distribution

Within the coastal zone, oceanographic features, such as fronts, can have major effects on the abundance and distribution of larval fish. We investigated the effects of fronts on larval fish assemblages by jointly collecting physical (ADCP and CTD) and biological (larvae) data in the nearshore waters of the south coast of South Africa, on four separate neap-tide occasions. Accumulation of fish larvae at predominantly internal wave-associated fronts was observed, with higher larval densities inshore of and within the front than farther offshore. On each occasion, larvae of coastal species with pelagic eggs (Mugillidae and Sparidae) were numerically dominant at the front itself, while inshore of the front, larvae of coastal species with benthic eggs (Gobiesocidae and Gobiidae) were more abundant. Offshore catches mainly comprised Engraulidae (pelagic species with pelagic eggs) larvae, which were generally restricted to the bottom, where current velocities were onshore on each occasion. On the occasion when fast (>100 cm/s) currents prevailed, however, accumulation of the larvae of coastal species occurred offshore of the front, and larvae were mixed throughout the water column. Thus, larval occurrence at these coastal frontal systems was strongly affected by the degree of mixing by currents, which on most occasions resulted in onshore retention. The results underline the importance of frontal systems in determining the nearshore distributions of fish larvae, particularly by retaining coastal fish species in the inshore region. The environmental variability observed at these frontal systems has potential implications for larval connectivity of fish populations.

scholarly journals Long-term changes of ichthyoplankton communities in an Iberian estuary are driven by varying hydrodynamic conditions

2020 ◽  
Author(s):  
M Monteiro ◽  
U M Azeiteiro ◽  
F Martinho ◽  
M A Pardal ◽  
A L Primo
Keyword(s):  
Environmental Variability ◽  
Larval Fish ◽  
Fish Larvae ◽  
Climate Change Impacts ◽  
Variable Structure ◽  
Local Environment ◽  
Strong Relationship ◽  
Marine Species ◽  
Economic Implications ◽  
Species Dominance

Abstract Ichthyoplankton assemblages are key components of estuaries worldwide, playing a vital role as nurseries for fish larvae. Nonetheless, estuaries can be highly affected by ongoing climate change. Impacts of climate variability on ichthyoplankton assemblages will have consequences for marine pelagic food webs and fish populations biology, namely recruitment. This study aims to investigate the influence of environmental variability on an interannual abundance of ichthyoplankton assemblages of the Mondego estuary (Portugal). For this, an ichthyoplankton sampling programme of 13 years (2003–2015) along six distinct sampling stations was analysed to evaluate spatial, seasonal and interannual changes of ichthyoplankton distribution over periods of wet, regular and dry conditions. The ichthyoplanktonic community was dominated by Pomatoschistus spp. across all seasons and conditions, with higher larval abundances during summer and spring. Main changes were related to species seasonality and phenology as well as an increase in the number of marine species during extreme events. The larval fish community showed a strong relationship with the regional and local environment over the study, presenting a distinct yet highly variable structure during the 2009–2013 period. Reported changes will likely trigger major changes in species dominance and abundance, with clear ecological and socio-economic implications.

Predicting the vertical distributions of reef fish larvae in the Straits of Florida from environmental factors

2010 ◽  
Vol 67 (11) ◽  
pp. 1755-1767 ◽  
Author(s):  
Klaus B. Huebert ◽  
Su Sponaugle ◽  
Robert K. Cowen
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Fish Assemblages ◽  
Environmental Variability ◽  
Fish Larvae ◽  
Straits Of Florida ◽  
Diel Vertical Migrations ◽  
Vertical Distributions

Three seasons of vertically stratified ichthyoplankton sampling at the edge of the Florida Current revealed consistent accumulations of some coral reef fish larvae under taxon-specific environmental conditions. Environmental variability ranging from predictable (seasonal differences in temperature, diel changes in light, and vertical gradients in many variables) to stochastic (changes in wind-driven turbulence and patchiness of zooplankton) was used to model larval distributions. In five taxa, including the commercially important Epinephelini (groupers), relative larval densities were predicted with significant accuracy based entirely on sampling depth. Models yielding these predictions were cross-validated among all seasons, indicating that larval vertical distributions were remarkably unaffected by other environmental factors, while revealing strong behavioral preferences for specific ranges of hydrostatic pressure. Pomacentridae (damselfish) larvae consistently occupied shallower depths at night than during the day, demonstrating diel vertical migrations. At the community level, depth and season were two major factors structuring larval coral reef fish assemblages. Predictable vertical distributions of larvae in the Straits of Florida can facilitate modeling the same taxa elsewhere in the Western Central Atlantic.

Independent Distributions of Fish Larvae and Their Prey: Natural Paradox or Sampling Artifact?

1988 ◽  
Vol 45 (1) ◽  
pp. 48-59 ◽  
Author(s):  
Kenneth T. Frank
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Food Resource ◽  
Zooplankton Biomass ◽  
Data Sets ◽  
Distributional Pattern ◽  
Coarse Mesh ◽  
Larval Food ◽  
Size Groups ◽  
Abundance And Distribution

Several recent studies have concluded that larval fish distributions are independent of the abundance and distribution of their prey. All of these studies used coarse-mesh (> 250 μm) nets, incapable of retaining the edible zooplankton for fish larvae, to provide quantitative estimates of the larval food resource. The assumption that zooplankton captured by coarse-mesh nets provided a reliable index of the edible zooplankton for fish larvae was tested and unsupported by the analysis of several independent data sets. In the waters off southwestern Nova Scotia the biomass of edible zooplankton for young larval fish was highly concentrated in the nearshore region, progressively lower levels were evident offshore on the shelf, and the mesoscale distributional pattern did not accurately reflect the total zooplankton biomass retained by a 333-μm-mesh net. Independent spatial distributions of discrete size groups of zooplankton are characteristics similar to zooplankton distributions reported for other geographic regions. A more logical explanation for the reports of "paradoxical" distributions of fish larvae and their prey is to be found in the inefficiency and bias in the sampling methods used to evaluate the larval food resource. Failure to properly evaluate the larval food resource has led to inappropriate testing of some longstanding hypotheses in fisheries biology.

scholarly journals DISTRIBUCIÓN Y DENSIDAD DE ICTIOPLANCTON EN EL ESTUARIO DE BAHÍA MÁLAGA, PACÍFICO COLOMBIANO (SEPTIEMBRE DE 2009-FEBRERO DE 2010)

2016 ◽  
Vol 43 (1) ◽  
Author(s):  
Diana Medina Contreras ◽  
Jaime Cantera ◽  
Eugenia Escarria ◽  
Luz M Mejía Ladino
Keyword(s):  
Fish Assemblages ◽  
Larval Fish ◽  
Fish Larvae ◽  
Larval Density ◽  
Temporal Distribution ◽  
Mesh Size ◽  
Temporal Variations ◽  
Taxonomic Composition ◽  
Total Density ◽  
The Relationship

The density, taxonomic composition, and spatial and temporal distribution of the estuarine ichthyoplankton of Bahía Málaga (Pacific coast of Colombia) are described, as well as the relationship between biological parameters and some physicochemical variables. Samples were collected at 12 stations along the principal navigation canal; these samples were taken in four areas following the design of Barletta-Bergan. Surface sweeps were carried out with a conical-cylindrical net (mesh size 500 µm, mouth diameter 0.6 m, length 3.5 m). Salinity and temperature were measured before each sweep. A total of 69019 larvae/1000 m³, representing 23 families, 36 genera and 40 species were collected during monthly sampling from September, 2009 to February, 2010. Carangidae (39.0%) was the most abundant family, followed by Sciaenidae (27.1%) and Engraulidae (20.1%). The most frequent families were Sciaenidae (26.6%), followed by Carangidae (22.8%) and Engraulidae (14.7%) which are important families in larval fish assemblages in tropical estuaries. Eighty percent of total density was provided by six species, of which Seriola morphotype 1 (Carangidae) and Cetengraulis mysticetus (Engraulidae) were the most abundant and dominant. No correlation was found between density and salinity (Spearman, R = 0.23) or temperature (Spearman, R = 0.51). Analysis of spatial and temporal variations of larval density shows significant differences among the months sampled (Anova, p = 0.0029; p < 0.05), but not among areas (Anova, p = 0.078), suggesting that Bahía Málaga offers adequate conditions for the presence of fish larvae.

scholarly journals Interannual variation of larval fish assemblages in the Gulf of Cádiz (SW Iberian Peninsula) in relation to summer oceanographic conditions

2006 ◽  
Vol 49 (2) ◽  
pp. 287-296 ◽  
Author(s):  
Paulo Mafalda Júnior ◽  
Juan Perez de Rubín
Keyword(s):  
Fish Assemblages ◽  
Larval Fish ◽  
Fish Larvae ◽  
Water Discharge ◽  
Estuarine System ◽  
Interannual Variations ◽  
Gulf Of Cadiz ◽  
Engraulis Encrasicolus ◽  
Gulf Of Cádiz ◽  
Sardinella Aurita

Two ichthyoplankton surveys were conducted during July 1994 and July 1995 in the Gulf of Cádiz with the aim of describing composition, abundance, distribution patterns and interannual variations of larval fish assemblages. Interannual differences were found in this study. In 1994, higher salinities were observed at external sites, though in 1995, higher values were observed at intermediate sites. The upper water column was warmer in 1994 and had less fish larvae density. During 1994, Sardinella aurita and Engraulis encrasicolus were abundant but spatial location was opposite. In 1995, abundance of both species was very different, but with similar spatial pattern. Cluster analysis revealed well-defined groups of stations and assemblages of larvae, primarily related to bathymetry. The "inshore assemblage" occupied the shallow coast area; its characteristics species being closely related to the estuarine system, mainly comprising Engraulis encrasicolus and Gobiidae. The "shelf assemblage" occupied the continental shelf and its characteristics species consisted of larvae whose adults inhabited the shelf province and spawn in the same zone, like Sardinella aurita and Trachurus spp. Interannual variations in composition and extension of the subgroups could be attributed to the main circulation patterns, continental water discharge and spawning strategies of fishes.

scholarly journals Environmental conditions influencing the larval fish assemblage during summer in the Gulf of Gabes (Tunisia: South central Mediterranean)

2015 ◽  
Vol 16 (3) ◽  
pp. 666 ◽  
Author(s):  
W. K. KOCHED ◽  
F. ALEMANY ◽  
S. BEN ISMAIL ◽  
R. BENMESSAOUD ◽  
Α. HATTOUR ◽  
...  
Keyword(s):  
Fish Assemblage ◽  
Fish Assemblages ◽  
Larval Fish ◽  
Fish Larvae ◽  
Surface Mixed Layer ◽  
Gulf Of Gabes ◽  
Predator Species ◽  
Pelagic Species ◽  
Gulf Of Gabès ◽  
South Central

An oceanographic survey was carried out during the summer of 2009, from June 25 to July 3 in the Gulf of Gabes. The study area is characterized by a wide continental shelf.A plankton sampling scheme was carried out to study the structure of the larval fish assemblages that characterizes the surface mixed layer, and to assess the influence of the environmental parameters on their spatial distribution.A total of 36 taxa were identified, 3 classified to the level of genus, 5 to family and 28 to species. The majority of identified fish larvae belonged to demersal species, mainly picarel Spicara smaris (23.76% of the total larval fish abundance), followed by red mullet Mullus barbatus (14.92%) and several species of the Sparidae family (9.15%). Small pelagic species as Sardinella Sardinella aurita and European anchovy Engraulis encrasicolus were also abundant (27.75 %) and dominated the fish larvae community in offshore stations. Five large pelagic species were found among the larvae, including bullet tuna Auxis rochei, Atlantic black skipjack Euthynnus alletteratus, albacore Thunnus alalunga, swordfish Xiphias gladius and the highly migratory Atlantic bluefin tuna Thunnus thynnus. All these apex predator species appear in 38.5% of the sampling stations and contribute about 7.9% of the total larval catches. The larval fish assemblage of the Gulf of Gabes is predominantly composed of neritic species in correspondence with the shallow depths of the study area. Canonical Correspondence Analysis (CCA) showed that larval distributions were mainly conditioned by depth. However, other factors, like hydrographic processes, play also a very important role in shaping the spatial pattern of larval fish distribution.

scholarly journals A snapshot on composition and distribution of fish larvae across the North Atlantic Ocean

2021 ◽  
Vol 22 (10) ◽  
Author(s):  
Mohd Nasarudin Harith ◽  
Cieran O'Donnell ◽  
GRAHAM JOHNSTON ◽  
Anne Marie Power
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Fish Assemblages ◽  
North Atlantic Ocean ◽  
Current Knowledge ◽  
Larval Fish ◽  
Fish Larvae ◽  
The North ◽  
The North Atlantic ◽  
Distribution Of Fish

Abstract. Harith MN, O’ Donnell C, Johnston G, Power AM. 2021. A snapshot on composition and distribution of fish larvae across the North Atlantic Ocean. Biodiversitas 22: 4496-4504. This study aims to describe the composition and distribution patterns of fish larvae communities across the North Atlantic Ocean. Several cruises were involved in the effort to collect the fish larvae samples. The sampling took place on the east side of the North Atlantic Ocean, towards the mid-Atlantic Ocean, and on the west side of the North Atlantic Ocean, near the eddies approaching Flemish Cap. A total of 9522 fish larvae were collected and identified from these surveys. These larvae came from 79 taxa and 29 families. Referring to the total abundance, considering all the sampled stations, Atlantic mackerel (Scomber scombrus) was the most abundant species (38.82% of the total fish larvae abundance), followed by blue whiting (Micromesistius poutassou) (15.9%). Referring to the Multi-dimensional scaling (MDS) ordination plots, two major stations clusters separate the on-shelf and off-shelf stations supported by SIMPER analysis. This study provides a snapshot of larval fish concentrations and assembly structure, but current knowledge suggests that the distribution of larval fish assemblages will be highly spatially variable, more research into plume front dynamics and their effects on the region's biota is needed to predict and understand changes.

Early life history studies of prey–predator interactions: quantifying the stochastic individual responses to environmental variability

2004 ◽  
Vol 61 (4) ◽  
pp. 659-671 ◽  
Author(s):  
Pierre Pepin
Keyword(s):  
Environmental Conditions ◽  
Early Life ◽  
Environmental Variability ◽  
Prey Availability ◽  
Larval Fish ◽  
Fish Larvae ◽  
Survey Methods ◽  
Field Studies ◽  
Variable Component ◽  
Field Evidence

Laboratory evidence shows that growth and survival of larval fish are strongly affected by variations in prey and predators; field evidence, in general, does not. This discrepancy may be partly due to the mismatch of scales at which manipulative and observational studies are conducted, or perhaps field studies are somehow not detecting the variable component of the larvae or their environment. I discuss potentially important variable features of fish larvae and their environment and show how mean values can be misleading. Using data from several field studies dealing with the growth and mortality of radiated shanny (Ulvaria subbifurcata) larvae, I illustrate how observational programs can miss important variation. I show evidence of how differences among individuals may lead to varying responses to fluctuations in prey availability. I also discuss issues concerning the level of variability in environmental conditions that may be described by standard survey methods used in the study of larval fish. The examples are intended to serve as illustration of the need to better describe the underlying stochastic structure of environmental conditions to understand early life dynamics.

scholarly journals Larval fish assemblages from channels and fjords of south Pacific Patagonia: effects of environmental conditions

2018 ◽  
Vol 53 ◽  
pp. 39 ◽  
Author(s):  
Gissella Castillo-Hidalgo ◽  
Mauricio F. Landaeta ◽  
Eduardo Anaya-Godínez ◽  
Claudia A. Bustos
Keyword(s):  
Water Column ◽  
Environmental Conditions ◽  
Fish Assemblages ◽  
Environmental Variability ◽  
Larval Fish ◽  
The Other ◽  
Southern Chile ◽  
Chemical Gradients ◽  
Temperature Depth ◽  
Patagonian Fjords

Chilean Patagonian fjords are characterized by strong stratification and chemical gradients which influence the ichthyoplankton distribution and abundance. Plankton samples were collected through bongo net oblique tows in 40 stations from onboard a bio-oceanographic cruise took place in inner fjords of southern Chile (47° to 51°S). Water column physical data were obtained with a conductivity-temperature-depth profiler (CTD) and turbidity was measured with a portable turbidimeter from 0 to 100 m depth. Stations were distributed by three zones: oceanic, channels and continental waters. A total of 1424 larvae were collected, representing 21 families. Dominant taxa were Maurolicus parvipinnis (31%), Sebastes oculatus (12%), Merluccius australis (11%), Lampanyctodes hectoris (10%), and Bathylagichthys parini (8%). Most of the environmental variability was determined by salinity, mainly in the area where continental waters are discharged. The water column in the oceanic zone presented mixed waters dominated by the myctophid L. hectoris and the sternoptychid M. parvipinnis. No significant effect of turbidity gradients on larval fish assemblages was evident during spring. The channel zone was both more saline, and density stratified with less turbidity, and lower abundance of species. Two ichthyoplanktonic assemblages were evident, one living in oceanic waters, and the other from channels and inner zones.

scholarly journals Larval fish assemblages in two nearshore areas of the Humboldt Current System during autumn-winter in northern Chile

2018 ◽  
Vol 53 ◽  
pp. 63 ◽  
Author(s):  
Lissette D. Paredes ◽  
Mauricio F. Landaeta ◽  
M. Teresa González
Keyword(s):  
Fish Assemblages ◽  
Larval Fish ◽  
Fish Larvae ◽  
Current System ◽  
Ekman Transport ◽  
Northern Chile ◽  
Spatial And Temporal Patterns ◽  
Humboldt Current ◽  
Engraulis Ringens ◽  
Humboldt Current System

This paper presents an analysis of spatial and temporal patterns in the fish larvae composition of two geographically adjacent nearshore areas within the Humboldt Current System (HCS), northern Chile. Five surveys were performed at Isla Santa María (ISM) and Punta Coloso (COL), Mejillones Peninsula. Ichthyoplankton were collected every 15 days in 2014 during the austral autumn-winter (May to August). A total of 412,410 fish larvae belonging to 36 taxa were identified, a high abundance compared with other HCS regions. Data also revealed similarities in species recorded compared with central Chile as well as differences compared with central Peru; a number of families were shared between these HCS regions and other systems (e.g., Canarias Current System). ISM was dominated by intertidal-subtidal species (e.g., Helcogrammoides cunninghami), while Engraulis ringens was most abundant at COL. Several species were positively correlated with dissolved oxygen (e.g., Auchenionchus microcirrhis), as well as temperature and Ekman transport (e.g., Sebastes oculatus), while the presence of others is negatively related to the same environmental parameters (e.g., Graus nigra). Results suggest that larvae differently utilize these two areas as a refuge or for feeding, and that adults might be coupling their spawning periods with short-term oceanographic features. Larval fish assemblages of nearshore areas in northern Chile are described here for the first time and highlight the important role of these two areas in the early developmental stages of fish species.

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