Multidecadal dynamics of larval gobies Pomatoschistus spp. in response to environmental variability in a shallow temperate bay

Genetic analysis reveals the diversity of larval Gobiidae in a temperate estuary

“…Week of the year counted alongside the commercial C. harengus larvae in the same region for more than five decades, but without any knowledge of the identity of the species (Laur et al, 2014). Here it is shown that P. minutus is the permanent and dominating species amongst larval gobiids in the north-east Gulf of Riga.…”

“…More specifically, the taxonomic composition of the larval goby complex was resolved in a shallow estuary in the Baltic Sea. Prior to this study, goby larvae were sampled and counted alongside the commercial C. harengus larvae in the same region for more than five decades, but without any knowledge of the identity of the species (Laur et al ., ). Here it is shown that P. minutus is the permanent and dominating species amongst larval gobiids in the north‐east Gulf of Riga.…”

“…The species‐level evidence obtained permits a new interpretation of published results. A four‐fold decrease in the abundance of goby larvae has been observed (Laur et al ., ) and the larval densities reported here represent some of the lowest values in the entire 50 year time series. The share of G. niger was low amongst larval gobiids, most likely because the environmental conditions in Pärnu Bay are not optimal for that species, nor have they been in the past 50 years.…”

“…Larvae of all species, however, were counted from samples, where Pomatoschistus Gill 1863 species were the second most abundant after C. harengus and were occasionally even the dominant taxon. The long-term data of their abundances in Pärnu Bay is available from the early 1950s (Laur et al, 2014). Since the coastal fish monitoring programme that has been running in some areas of the Baltic Sea over the past two decades (HELCOM, 2006) does not account for the small demersal fish species, larval monitoring is the single source of information on the long-term dynamics of these short-lived small-sized fishes.…”

“…Based on the taxonomic identifications of juvenile and adult fishes that sporadically occur in demersal trawl catches, or the stomachs of pikeperch Sander lucioperca (L. 1758), it was assumed that the goby larvae consisted of two species, the common goby Pomatoschistus microps (Krøyer 1838) and sand goby Pomatoschistus minutus (Pallas 1770) (Laur et al, 2014). Owing to morphological similarities, however, the larvae of these species cannot be identified to the species level on the basis of external morphology alone (Beyst et al, 1999;Faria et al, 2006).…”