The entrainment-development of larval fish assemblages in two contrasting cold core eddies of the East Australian Current system

Author(s):  
V Garcia ◽  
HT Schilling ◽  
DO Cruz ◽  
SM Hawes ◽  
JD Everett ◽  
...  
2014 ◽  
Vol 71 (7) ◽  
pp. 1696-1705 ◽  
Author(s):  
Paloma A. Matis ◽  
Will F. Figueira ◽  
Iain M. Suthers ◽  
Joshua Humphries ◽  
Anthony Miskiewicz ◽  
...  

The relationship between larval fish assemblages and coastal oceanography is the basis for much of our understanding of connectivity and productivity of fish populations. Larval fish assemblages were sampled from the upper mixed layer (<50 m depth) at three prominent circulation features [separation of the East Australian Current (EAC), anticyclonic eddy, and cyclonic eddy] off the southeast Australian coast across three bathymetric zones (shelf, slope and ocean) for each feature. The separation of the EAC from the coast at ∼32°S was characterized by warmer, less saline water compared with the cyclonic and anticyclonic eddies further to the south (∼34 and ∼35°S, respectively), which were both characterized by cooler Tasman Sea water and greater fluorescence. The anticyclonic eddy had separated from the EAC three months prior to sampling, which facilitated the movement of a cyclonic eddy from the Tasman Sea westwards to the shelf at ∼34°S. The larval assemblage in the EAC had high numbers of fish of the families Labridae and Stomiidae. The cyclonic eddy was characterized by larval clupeids, carangids, scombrids and bothids, indicating recent entrainment of shelf waters and proximity to major spawning regions. In contrast, the anticyclonic eddy had fewer larval fish, with little evidence for entrainment of shelf assemblages into the near-surface waters. Myctophids were found in high abundance across all oceanographic features and bathymetric zones. The evidence of selective entrainment of coastal larval fish into the near-surface waters of a cyclonic eddy compared with a similar anticyclonic eddy indicates a potential offshore nursery ground.


2018 ◽  
Vol 53 ◽  
pp. 63 ◽  
Author(s):  
Lissette D. Paredes ◽  
Mauricio F. Landaeta ◽  
M. Teresa González

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.


2011 ◽  
Vol 20 (5) ◽  
pp. 434-447 ◽  
Author(s):  
T. J. MULLANEY ◽  
A. G. MISKIEWICZ ◽  
M. E. BAIRD ◽  
P. T. P. BURNS ◽  
I. M. SUTHERS

2013 ◽  
Vol 64 (10) ◽  
pp. 932 ◽  
Author(s):  
L. B. Bucater ◽  
J. P. Livore ◽  
C. J. Noell ◽  
Q. Ye

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.


2021 ◽  
Author(s):  
Yu-Kai Chen ◽  
Chia-Yi Pan ◽  
Yi-Chen Wang ◽  
Hsiu-Ju Tseng ◽  
Bo-Kun Su ◽  
...  

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.


2014 ◽  
Vol 36 (1) ◽  
pp. 104-117 ◽  
Author(s):  
Daniela Giordano ◽  
Adriana Profeta ◽  
Barbara Busalacchi ◽  
Roberta Minutoli ◽  
Letterio Guglielmo ◽  
...  

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