Distribution Of Fish Larvae Research Articles

Diversity and distribution of larval and juvenile fish in nearshore waters of the Southeastern Caspian Sea and Gorgan Bay

Occurrence and distribution of larval and juvenile fish was investigated in nearshore waters of the southeastern Caspian Sea including the Gorgan Bay. Samples were collected during seven surveys using a fine mesh beach-seine in five sampling sites from July 2014 to June 2015. A total of 15500 individuals mostly juvenile were captured, representing 18 species from 8 families. Most juveniles belonged to Liza saliens, Atherina caspia, Neogobius pallasi and Neogobius melanostomus. The juveniles of Alburnus chalcoides, Vimba persa, Syngnathus caspius and gobies Neogobius caspius and Ponticola syrman occurred in low number (relative abundance 0.1% - 9.3%). Highest number of juveniles were caught in summer season. The occurrence of larval fish in coastal waters of southern Caspian Sea was recorded for the first time (Atherina caspia with minimum length of 12 mm in Caspian and 9.5 mm in Gorgan Bay). In spring, early juveniles of mullet, Liza aurata, increased in the Caspian sites but they moved up to deeper waters by the end of the season. Based on results, the density of juvenile fish (specially Liza saliens) in Gorgan Bay was several times more than Caspian sites so it could be considered an important nursery ground in the region.

Variation in the structure of the ichthyoplankton community in the lower Paraíba do Sul River

ABSTRACT The Paraíba do Sul River is affected by extensive water collection for supply, organic and industrial pollution, and dams. Nonetheless, the ichthyofauna maintains biodiversity and sustains artisanal fisheries. This study analyzes the composition, abundance and distribution of fish larvae, an important approach to determine the reproductive period and spawning sites. The sampling occurred from August 2011 through February 2013 in five sites at a transect between the banks on the lower reach of the Paraíba do Sul River. A total of 5,412 larvae belonging to 20 taxa was captured. The predominant order was Characiformes. Larvae of Prochilodus spp. and Leporinus spp. were the most abundant; larvae of Brycon insignis, an endangered species, were present. Fewer larvae were collected in the second reproductive cycle during a severe drought. The absence of eggs indicates that the study area is not used for spawning, and highlights the need for studies in the main channel and in the tributaries of the Paraíba do Sul River. Fish larvae need to have access to the marginal lagoons along the lower stretch of the river, an area which is the object of disputes between fishermen and farmers.

Fish larvae distribution among different habitats in coastal East Africa.

Fish larvae abundances, diversity and trophic position across shallow seagrass, coral reef and open water habitats were examined to characterize their distribution in coastal East Africa. Larvae were identified to family and analysed for abundance differences between sites and habitats, trophic level using stable-isotope analysis and parental spawning mode. Abundances differed greatly between sites with the highest numbers of larvae occurring in the open-water and seagrass habitats. Larval fish diversity was high across habitats with 51 families identified with small differences between sites and among habitats. Notably, larvae of abundant large herbivorous fishes present in reef and seagrass habitats were almost completely absent at all sampling locations. In the seagrass, demersal spawned larvae were more abundant compared with the reef and open-water habitats. Stable-isotope analysis revealed that fish larvae have a varied diet, occupying trophic level two to three and utilizing planktonic prey. This study offers new insights into distributional aspects of fish larvae along the East African coast where such information is sparse.

Physical-biological interactions in the ocean: case studies from the northern Canary Current Upwelling Ecosystem

Physical-biological interactions in the ocean: case studies from the northern Canary Current Upwelling Ecosystem

Microplastic contamination in an urban estuary: Abundance and distribution of microplastics and fish larvae in the Douro estuary

Estuaries are productive environments used by many fish as nursery grounds. The initial stages of fishes are highly vulnerable to (a)biotic factors, and anthropogenic pressures, influencing fish larvae assemblages along the estuary. Microplastics (MPs < 5 mm) are particularly dangerous to early life stages of fishes because their ingestion can induce gut blockage, limiting food intake or exposing organisms to contamination due to MPs capacity to absorb pollutants. Present work aimed to investigate the contamination of an urban impacted estuary (Douro estuary, NW Portugal) by MPs, and study the abundance and distribution of MPs and fish larvae in this estuary. Monthly sampling surveys were performed from December 2016 to December 2017, in nine stations along the estuary. Sub-surface planktonic horizontal trawls were performed to collect fish larvae and MPs. Planktonic samples were sorted, and fish larvae identified. MPs density was determined using a protocol optimized in our laboratory. A total of 1498 fish larvae belonging to 32 taxa were collected, with a mean density of 11.66 fish larvae 100 m−3. During the spring-summer period, it was observed the typical increase in the density and diversity of the larval assemblage. Diversity was generally low, with the high dominance of very few taxa, namely the common goby, Pomatoschistus microps. Different types of MPs were found, namely fibers, soft/hard plastic, colorful/transparent plastic, in a total of 2152 particles, with a mean density of 17.06 MPs 100 m−3. Hard MPs and fibers were the most predominant types, representing 83% of the total MPs collected. In some months the number of MPs surpassed the number of fish larvae, with an average ratio of 1.0 fish larvae:1.5 MPs. Such results are concerning, highlighting that a higher availability of MPs may facilitate their ingestion by fish and therefore increase possible impacts in these communities.

Spatiotemporal distribution of fish eggs and larvae in the Huanghe (Yellow) River estuary, China in 2005–2016

Decreasing fish resources in estuaries is a subject of anthropogenic activities. Studies of the spatiotemporal distribution of fish eggs and larvae can help identify the status and processes underlying recruitment in a fishery. As the fifth largest river estuary in the world, the Huanghe (Yellow) River estuary (HRE) is a typical estuary that has been seriously affected by human activities. Annual surveys on ichthyoplankton and environmental factors were conducted in the months of May of 2005 and 2009–2016 in the HRE to investigate the spatiotemporal distribution of fish eggs and larvae and the associated influencing factors. A total of 23 and 20 species of eggs and larvae, respectively, were collected. The dominant orders were Perciformes (51.2%) and Clupeiformes (25.6%). The average number of fish species eggs and larvae were 6.0 and 4.1 in average abundance of 0.91 and 0.13 ind./m3, respectively. The dominant species were mainly low-commercial-value small-sized fishes, such as Clupanodon punctatus, Harengula zunasi, and Acanthogobius, whereas certain traditional commercial fishes, such as Trichiurus lepturus, and Clupea pallasii, were not seen. Analysis of the fish egg and larval community revealed four temporal assemblages and two spatial assemblages. Salinity was the main factor on the spatial distribution of ichthyoplankton communities, the species number and Shannon-Weiner diversity index (H′) of the fish egg and larval community near the river mouth with lower salinity were significantly lower than the community far away from the river mouth with higher salinity. In addition, increases of water temperature promoted the number and abundance of fish species eggs, and the areas of abundant prey tended to have a more diversified and abundant of ichthyoplankton species. In overall, overfishing, dam construction, and other human activities were the main drivers that led to the substantial decline in fishery resources in the HRE.

Characterizing spatial structures of larval fish assemblages at multiple scales in relation to environmental heterogeneity in the Strait of Georgia (British Columbia, Canada)

Spatial structures of larval fish in the Strait of Georgia (British Columbia, Canada) were quantified in the springs of 2009 and 2010 to investigate linkages to environmental heterogeneity at multiple scales. By applying a multiscale approach, principal coordinate neighborhood matrices, spatial variability was decomposed into three predefined scale categories: broad scale (&gt;40 km), medium scale (20∼40 km), and fine scale (&lt;20 km). Spatial variations in larval density of the three dominant fish taxa with different early life histories (Pacific herring (Clupea pallasii), Pacific hake (Merluccius productus), and northern smoothtongue (Leuroglossus schmidti)) were mainly structured at broad and medium scales, with scale-dependent associations with environmental descriptors varying interannually and among species. Larval distributions in the central-southern Strait were mainly associated with salinity, temperature, and vertical stability of the top 50 m of the water column on the medium scale. Our results emphasize the critical role of local estuarine circulation, especially at medium spatial scale, in structuring hierarchical spatial distributions of fish larvae in the Strait of Georgia and suggest the role of fundamental differences in life-history traits in influencing the formation and maintenance of larval spatial structures.

Fish larval composition and distribution assessment in the northern waters of Ambon Island

The Banda Sea ecosystem has been highlighted in the past decade for its potential role in providing economically important fish stock for human consumption. However, literature studies indicated lack of references regarding fish larvae abundance and composition in coastal areas of islands impacted directly by the Banda Sea. The study covers fish larval survey carried out at the northern waters of Ambon Island in April 2017. The composition, distribution, and abundance of fish larvae were described based on five horizontal and one vertical sampling stations. Twenty-eight families were identified and two of them were the most abundant: Atherinidae (23% of the total larvae) and Apogonidae (21% of the total larvae). Most of the other families were known to be neritic and in particular were fishes commonly found to be associated with coral reef ecosystems. This finding indicated the profile of the northern waters area, which has extensive coral reef coverage, as well as estuary and mangrove area.

Distribution and Abundance of Fish Larvae in South of Alas Strait, West Nusa Tenggara

The early life of fish larvae is important to understand the entire life history of the fish. At this phase, larvae movement is very weak and dependent on the movement of water currents. This study aims to determine the distribution and abundance of fish larvae in the waters south of the Port of Tanjung Luar, West Nusa Tenggara, Indonesia. Sampling of fish larvae were done at five stations at waters around Alas Strait and Indian Ocean south of East Lombok. Sampled were collected from 5 different depth: 0-200 m, 201-1000 m, 1001-2000 m, 2001-3000 m and &gt;3000 m. A total of 122 fish larvae were collected which belong to 26 families and varied compositions among observation stations. The samples was dominated by Scombridae family (18 %), followed by Carrangidae and Blenniidae (13.1% and 6.6%, respectively). The highest abundance was occurred in station V (0-200 m) of 125 individuals.1000-1m3. It showed that inshore/shallow waters have more abundance than offshore/deep waters. The findings from this study can be basic information for the authorities to establish sustainable fisheries policy. Keywords: fish, larvae movement, sustainable fishery, early life.

The post-larval and juvenile fish assemblage in the Sukhothai Floodplain, Thailand

This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae (47.27%), Cobitidae (7.88%), Siluridae (6.67%), Bagridae (6.06%) and Mastacembelidae (3.33%) families. The mostabundant larval species were the Striped flying barb Esomus metallicus (16.90%), the Siamese mud carp Henicorhynchus siamensis (8.48%) and the Sumatran river sprat Clupeichthys goniognathus (8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid Rasbora species.

Sensitivity of modelled North Sea cod larvae transport to vertical behaviour, ocean model resolution and interannual variation in ocean dynamics

AbstractTransport with ocean currents affects the spatial distribution and survival of fish eggs and larvae and thereby population connectivity. Biophysical models are commonly used to understand these dynamics. Advancements such as implementing vertical swimming behaviour and higher resolution ocean circulation models are known to improve model performance, however, the relative importance of vertical behaviour vs. ocean model resolution is elusive. Here, we use North Sea cod (Gadus morhua) as a case study to assess how vertical movement, ocean model resolution and interannual variation in ocean dynamics influence drift patterns and population connectivity. We couple a fine (1.6 km, 3 h) and coarser (4 km, 24 h) ocean model to an individual-based model for cod eggs and larvae, and compare simulations with and without vertical movement of eggs and larvae. The results are moderately influenced by vertical movement and ocean model resolution but differ substantially between years. While ocean model resolution is consistently more influential than vertical movement, the effect of vertical movement strongly depends on the spatiotemporal scale of the analyses. This study highlights which aspects of biophysical modelling of connectivity that most critically affect the results, allowing better investing computational resources and proposing goal-based guidelines for future studies.

Size distribution of larvae entrained and the role of fine mesh screening in excluding larvae at an operating power plant

ABSTRACTPatrick PH, Powell J, Mason E, Tai M-K, Stanko T, Dziedzic HD. 2018. Size distribution of larvae entrained and the role of fine mesh screening in excluding larvae at an operating power plant. Lake Reserv Manage. 00:00–00.This study clearly demonstrated the importance of measuring larval length and head capsule dimension in assessing larval fish entrainment and in determining the performance of screen mesh openings in excluding larvae. We determined the size distribution of fish larvae entrained at the Campbell Power Plant on Lake Michigan and assessed the potential of 4 screen mesh sizes (range, 1.59–9.53 mm [1/16–3/8 in] plus an open-pipe control) in reducing the number and size of entrained larvae. Fish larvae were collected using an entrainment pump net-in-water design. Different sizes of larvae, based on both total length and head capsule size, were entrained at the Campbell Plant, and size ranges varied with species. Entrainment densities also varied with season and diurnally. The screens tested in our study were not effective in excluding larval fish. There was no statistical difference (P > 0.05) in the number of larvae entrained among the different screen sizes tested. Most organisms entrained during screen mesh testing were small (<10 mm total length) and had head capsule sizes (≤1.0 mm) smaller than the smallest screen mesh size tested.

Patterns in larval reef fish distributions and assemblages, with implications for local retention in mesoscale eddies

Benthic marine populations are often replenished by a combination of larvae from local and distant sources. To promote retention of locally spawned larvae in strong, unidirectional boundary current systems, benthic marine organisms must utilize biophysical mechanisms to minimize advective loss. We examined patterns in larval fish abundance, age distribution, and assemblage in relation to environmental variables in the Straits of Florida to better understand the factors underlying larval transport and retention in a boundary current system. Depth was the primary structuring element; larval assemblages were more distinct across vertical distances of tens of metres than they were over horizontal distances of tens to hundreds of kilometres. However, depth distributions were species-specific, and larval assemblages inside and outside of mesoscale eddies were distinct. Age distributions were consistent with the hypothesis that mesoscale eddies provide opportunities for retention. Our data indicate that the effect of eddies on larval retention is likely taxon-specific and temporally variable, as synchronization of reproductive output, larval distribution, and timing of eddy passage are prerequisite to entrainment and subsequent retention of locally spawned larvae.

Preferential distribution of fish larvae in the California Current System: Time, space, and temperature

AbstractThe preferential larval distributions of 22 fish species in the California Current System were identified in their temporal, spatial, and thermal domains using single parameter quotient analysis. This analysis allowed the characterization of their reproductive habitats based on ranges of preference, tolerance, and avoidance. In the temporal domain, the species’ preference intervals were wider than those previously reported, and all species showed preferences during two or more seasons of the year. In the spatial domain, the preferential distributions of the species were also wider, and some of them had different preferred zones from those described in previous works. Because one group of species was preferably distributed in coastal zones, and the other group was preferably distributed in oceanic zones, the biological production mechanisms sustaining these groups differ, namely, coastal upwelling and geostrophic fluxes of subarctic origin, respectively. In the thermal domain, the larval distribution preferences of 20 of 22 species have been determined for the first time, providing important information on their thermal tolerance window during the larval stage, a window that changes in width throughout each of the ontogenetic stages of fish. The distribution in each domain suggests association patterns between species, but additional studies are necessary to validate these patterns.

Effects of light-dark cycle on the spatial distribution and feeding activity of fish larvae of two co-occurring species (Pisces: Hypophthalmidae and Sciaenidae) in a Neotropical floodplain lake.

Most studies on mechanisms regulating fish larvae processes have focused on assessing the isolated effects of food distribution and feeding behavior. However, in natural ecosystems, fish larvae may strongly interact with zooplankton organisms in an array of complex, direct and indirect interdependencies. This study analyzed the spatial distribution, diet and feeding behavior of early stages of Hypophthalmus edentatus and Plagioscion squamosissimus, two fish species co-occurring in an isolated floodplain lake, during the light-dark cycle. Larvae fed more actively during dark periods (dusk and night) when they migrated toward the surface of the lake, and remained on the bottom and fed less during light periods (day and dawn). Cladocerans represented the most frequent prey in the diet of H. edentatus larvae. In turn, P. squamosissimus larvae initially preferred cladocerans and, as they developed, included calanoid copepods in the diet. Significant differences were detected in the frequencies of food items consumed during larval development, which could be related to a better ability of the most developed stages to explore the environment in search of other prey.

Vertical distribution of mesozooplankton and ichthyoplankton communities in the South-western Atlantic Ocean (23°14′1″S 40°42′19″W)

A study was conducted over eight consecutive days in February 2010 in which daily variations in the vertical distributions of heterotrophic bacteria, mesozooplankton and ichthyoplankton at 1–1200 m in the South-western Atlantic Ocean were investigated. Diurnal and nocturnal samples were collected at an oceanographic station at four regional depths: Tropical Water (TW) (1 m), South Atlantic Central Water (SACW) (250 m), Antarctic Intermediate Water (AAIW) (800 m) and Upper Circumpolar Deep Water (UCDW) (1200 m). Bacterial, mesozooplankton and larval fish densities significantly differed between sample depths but not between sampling tow times. In total, 154 zooplankton species and 18 larval fish species were identified. The highest number of taxa was obtained from the night-time TW trawls. This depth zone had the highest densities of mesozooplankton, larval fish and bacterioplankton (auto and heterotrophic), associated with the highest temperature and salinity and the lowest inorganic nutrient concentrations. Two sample groups were identified based on their mesozooplankton and larval fish compositions: night-time TW and other water masses (daytime TW, SACW, AAIW and UCDW). Thirty-two indicator species were detected in night-time TW. The copepodNullosetigera imparwas, to the best of our knowledge, identified for the first time on the Brazilian coast. Our results showed significant variability in the abundance and vertical distribution of mesozooplankton, bacterioplankton and larval fish along the water column in an oceanic area. We have provided new data and insights on the composition and vertical distribution of mesozooplankton, larval fish and bacterioplankton in deep waters in the South-western Atlantic Ocean.

Distribution of Fish Larvae in the Southern Coastal Waters (Yeosu, Namhae and Tongyoung) of Korea in Spring and Summer

Distribution of Fish Larvae in the Southern Coastal Waters (Yeosu, Namhae and Tongyoung) of Korea in Spring and Summer

Molecular identification of Bathymaster spp. (Bathymasteridae) larvae in the Gulf of Alaska and eastern Bering Sea

Information on the phenology and distribution of fish larvae is critical to understanding recruitment dynamics of populations. Larvae of the family Bathymasteridae (ronquils) are an abundant component of the ichthyoplankton community in the eastern North Pacific Ocean and Bering Sea, but cannot be readily identified to the species level using morphological or meristic approaches. We developed a restriction fragment length polymorphism (RFLP) protocol based upon variation in the mitochondrial (COI) gene to identify larvae of three species in the genus Bathymaster: smallmouth ronquil (B. leurolepis), Alaskan ronquil (B. caeruleofasciatus) and searcher (B. signatus). A subsample of larvae from annual ichthyoplankton surveys was screened using the RFLP protocol, and 259 of 260 individuals were correctly identified to species, providing the first data on the seasonal occurrence of early life-history stages in ichthyoplankton surveys for these species. Peak abundance for two species in surveys conducted from 2006 to 2014 occurred in spring. Larvae of smallmouth ronquil were absent from spring surveys and occurred as only 8% of the total numbers collected in later seasons. Our results indicate that larvae of Alaskan ronquil (B. caeruleofasciatus) were more likely to occur at deeper sampling stations (bottom depth > 180 m) in spring, while searcher (B. signatus) larvae were more common at shallower stations (bottom depth ≤ 100 m).

Modeling the spatial distribution of larval fish abundance provides essential information for management

Productive fisheries are strongly linked to the ecological state of the essential habitats. In this study, we developed a methodology to assess the most important reproduction habitats of fish by using larval survey data and Bayesian species distribution models that predict the spatial distribution and abundance of fish larvae. Our case study with four commercially and ecologically important fish species in the coastal zone of the northern Baltic Sea demonstrated that the production of fish stocks can be concentrated to an extremely limited area compared with the entire suitable production area. The area suitable for larval production varied from 3.7% to 99.8% among species, but the smallest area responsible for 80% of the cumulative larval production was two to five times more limited, varying from 1.4% to 52.9% among species. Hence, instead of the traditional approach of modeling only habitat suitability for fish production, marine spatial planning and management should take into account the areal production potential. Moreover, the developed methodology enables linking of the total production potential across the whole distribution area to fisheries stock assessment and management.

Spatial and temporal variability in ichthyoplankton communities ingressing through two adjacent inlets along the southeastern US Atlantic coast

Estuaries along the US east coast serve as essential nursery habitats for the early life history stages of many marine fishes. In the South Atlantic Bight (SAB), many studies have demonstrated the importance of these habitats for juveniles, but larval fish communities have received little attention, particularly around northeast Florida. To determine community structure, and seasonal distribution and abundance of larval fish in the Guana–Tolomato–Matanzas (GTM) estuary at its two inlets (St. Augustine and Matanzas), ichthyoplankton were sampled bi-weekly for one year at both inlets during nighttime spring flood tides. Samples were collected with a plankton net (1 m diameter, 1 mm mesh) suspended 1 m below the surface. Seventy-two taxa were collected, with four families comprising 85% of the collection: Sciaenidae (36.2%), Engraulidae (19.9%), Gobiidae (18.0%), and Gerreidae (10.7%). The two inlets differed in larval densities and taxonomic richness, although both were greatest during the summer. Spring and summer pulses in recruitment were observed for nearshore summer spawners. Marine offshore-spawned species exhibited peak recruitment in winter. The ichthyoplankton communities of the GTM estuary were most similar to those in southern SAB estuaries, and showed pronounced seasonal changes in composition, as is common in estuaries worldwide.