Influence of offshore breakwaters on fish assemblage structure in the surf zone of a sandy beach in Tokyo Bay, central Japan

Abstract

To determine the effects of shore-parallel offshore breakwaters on the surf-zone fish assemblage structure of a sandy beach, three study sites (sheltered inshore of breakwater, between adjacent breakwaters, and exposed without breakwaters) were sampled at Ohnuki . Although some physical variables (wave height, turbidity, and water depth) differed among the three sites, no differences were apparent among the sites in the numbers of fish species and individuals, or in the abundance of epibenthic invertebrates (a main fish prey). In addition, species and individual numbers of two dominant feeding groups (mysid and copepod feeders) showed no significant among-site differences. Cluster and ordination analyses confirmed the similarity in fish species composition among the three sites. Furthermore, the mean standard length of all fishes collected throughout the study period did not differ significantly among the sites, the overall results indicating that the presence of breakwaters had little effect on surf-zone fish assemblage structure in the study area, despite some breakwater-related differences in the abiotic environment.

Surf zone fish abundance and diversity at two sandy beaches separated by long rocky jetties

“…These two contrasted conditions may occur at both sides according to wind conditions (Lima & Vieira 2009; Mont'Alverne et al , 2012) resulting in no overall differences in fish assemblage structure in both sides of the jetties. In fact, some recent studies have suggested that surf zone fish assemblage is not particularly affected by the presence of jetties or breakwaters (Cenci et al , 2011; Mikami et al, 2012).…”

The ecology of fish in the surf zones of ocean beaches: A global review

“…Many other families (n = 43), including turbot (Scopthalmidae), are scarce in most surf zones, but can be common in some locations (Vinagre, Silva, Lara, & Cabral, 2011) ( Figure 4). By contrast, few families (n = 10), for example mullet and herring (Clupeidae), are common and numerically dominate surf fish assemblages (Mikami, Nakane, & Sano, 2012) (Figure 4).…”

“…Beach nourishment studies either report no significant effects on fish assemblages (Ross & Lancaster, 2002) or describe impacts to fish abundance, diversity and diet (Manning, Peterson, & Fegley, 2013;Wilber, Clarke, Ray, & Burlas, 2003b). Studies on the effects of artificial structures either report no impact of jetties or breakwaters on fish assemblages (Mikami et al, 2012;Rodrigues & Vieira, 2012) or outline changes to fish abundance and diversity that are attributed to the construction of groins (Tatematsu et al, 2014).…”

A Tropic and Subtropics 2oC Difference Affecting the Spatiotemporal Distribution of Small Demersal Fish Assemblages - Central Western Taiwan Example

“…The second dominant species of the ZRf group was P. microcephalus. They are widely distributed in tropical and subtropical areas in the coastal waters of Beibu Gulf, south of Hainan Island, China at 17-18 o N 53 and Ohnuki Beach, Tokyo Bay, Japan at 35 o N 54 . The group of P. microcephalus composed two cohorts in our November survey.…”