Can we assess the ecological status of estuaries based on larval fish assemblages?

Estuaries are transition zones that link freshwater and marine ecosystems and are often used as nursery areas by fish. The Murray–Darling Basin, which is heavily affected by flow regulation and water extraction, is the largest river system in Australia and terminates at the Murray Mouth estuary. Protracted drought conditions resulted in extremely low flows to the Murray Mouth that affected water condition, fish abundance, community structure and fish use of the estuary (e.g. nursery areas). The aims of the present study were to examine temporal changes in larval fish assemblages in this estuary. The assemblages were dominated by two gobiid species, Arenigobius bifrenatus and Tasmanogobius lasti. There was a noticeable absence or low abundance of freshwater, diadramous and large-bodied marine species that use this estuary for reproductive functions. Monthly differences in larval fish assemblages, between August–September and October–November, were attributed to increases in the abundances of A. bifrenatus in October and November and oscillation in T. lasti during the entire sampling period. The outcomes of the present study suggested that larval fish assemblages in drought conditions are limited to small-bodied species tolerant of high salinities and that freshwater flows are needed for the estuary to function as a nursery for other species.

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Interannual variability of larval fish assemblages associated with water masses in winter in the Taiwan Strait during 2007–2013

Fisheries Science ◽

10.1007/s12562-020-01489-z ◽

2021 ◽

Author(s):

Yu-Kai Chen ◽

Chia-Yi Pan ◽

Yi-Chen Wang ◽

Hsiu-Ju Tseng ◽

Bo-Kun Su ◽

...

Keyword(s):

Fish Assemblages ◽

Larval Fish ◽

Taiwan Strait ◽

Assemblage Structure ◽

Sea Surface ◽

Coastal Current ◽

Annual Variations ◽

Frontal Zones ◽

The Taiwan Strait

AbstractIn this study, the interannual variations of ichthyoplankton assemblages in the Taiwan Strait (TS) during the winters of 2007–2013 were determined. The cold China Coastal Current (CCC) and Mixed China Coastal Water (MCCW) intruded into the TS and impinged with the warm Kuroshio Branch Current (KBC) with annual variations. Consequently, the ichthyoplankton community in the TS was mainly structured into two assemblages characterized by differing environmental conditions. The composition of the warm KBC assemblage was relatively stable and was characterized by Diaphus B and Bregmaceros spp. By contrast, the cold MCCW assemblage demonstrated considerable variations over the years, with demersal Gobiidae and Scorpaenidae families considered the most representative. In addition, Benthosema pterotum and Trichiurus spp. were common in both KBC and MCCW assemblages. The distribution of the KBC assemblage demonstrated sharp boundaries in the frontal zones, whereas changes in the assemblage structure between the frontal zones were gradual for the MCCW assemblage, particularly when demersal taxa were dominant. Sea surface temperature and salinity were most strongly associated with variability in the assemblage structure during the study period. Thus, this paper provides a better understanding of long-term larval fish dynamics during winter in the TS.

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Summer larval fish assemblages in the Southern Tyrrhenian Sea (Western Mediterranean Sea)

Marine Ecology ◽

10.1111/maec.12123 ◽

2014 ◽

Vol 36 (1) ◽

pp. 104-117 ◽

Cited By ~ 5

Author(s):

Daniela Giordano ◽

Adriana Profeta ◽

Barbara Busalacchi ◽

Roberta Minutoli ◽

Letterio Guglielmo ◽

...

Keyword(s):

Mediterranean Sea ◽

Fish Assemblages ◽

Larval Fish ◽

Western Mediterranean ◽

Tyrrhenian Sea ◽

Western Mediterranean Sea ◽

Southern Tyrrhenian Sea

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Demersal and larval fish assemblages in the Chukchi Sea

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/j.dsr2.2009.08.006 ◽

2010 ◽

Vol 57 (1-2) ◽

pp. 57-70 ◽

Cited By ~ 49

Author(s):

Brenda L. Norcross ◽

Brenda A. Holladay ◽

Morgan S. Busby ◽

Kathryn L. Mier

Keyword(s):

Fish Assemblages ◽

Larval Fish ◽

Chukchi Sea

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Adult and larval fish assemblages vary among small tributary mouths of Green Bay, Lake Michigan

Canadian Journal of Zoology ◽

10.1139/cjz-2020-0143 ◽

2021 ◽

Author(s):

Amelia T McReynolds ◽

Megan L. Hoff ◽

Angelena A. Sikora ◽

Cynthia I. Nau ◽

Michael J. Pietraszek ◽

...

Keyword(s):

Fish Assemblage ◽

Lake Michigan ◽

Fish Assemblages ◽

Water Movement ◽

Larval Fish ◽

Spatial Dynamics ◽

Spatial And Temporal Variation ◽

Adult Fish ◽

Green Bay ◽

Small Tributary

Small tributaries of the Great Lakes serve as important habitat during critical life stages of many fish species, though temporal and spatial dynamics of the assemblage that uses these systems are seldom investigated. This study quantifies larval and adult fish assemblages captured by fyke net and light traps among small tributary mouths of Green Bay, Lake Michigan. Ten tributaries harbored a total of forty-five species representing seventeen families, with the most abundant including spottail shiner (Notropis hudsonius (Clinton 1824)) in adult assemblages and white sucker (Catostomus commersonii (Lacepède 1803)) in larval assemblages. Larval fish assemblage structures differed over five biweekly sampling events in May and June. Adult fish assemblage structures varied among tributaries but not among spring, summer, and fall samples. Larval and adult species assemblages at these rivermouths are likely influenced by hydrology, habitat structure, and species-specific ecology. Water movement may transport larvae into rivermouths, as larval assemblages were dominated by species that spawn in coastal habitats. Adult species richness varied with longitude, with the greatest diversity in tributaries on the west shore. This investigation of fish assemblages highlights the spatial and temporal variation that occurs in these systems and their role in shaping fish populations in Green Bay.

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