Overlapping Habitat Use of Multiple Anadromous Fish Species in a Restricted Coastal Watershed

Abstract

The purpose of this study was to document timing and habitat of alosines (Hickory Shad Alosa mediocris, American Shad A. sapidissima, Alewife A. pseudoharengus, and Blueback Herring A. aestivalis) and Striped Bass Morone saxatilis in the lower Tar River, a North Carolina coastal watershed partially restricted by an unused industrial dam. Alosines and Striped Bass are usually separated in time or space during spawning activity but occasionally overlap in some systems. Results show that both eggs and larvae of Hickory Shad and Striped Bass predominated catches, followed by American Shad. Alewife and Blueback Herring had negligible catches of eggs and larvae, but a separate study conducted 48 river kilometers downstream of the study area collected larvae of both species. Eggs and larvae of target species overlapped spatially and were most abundant in downstream tributaries, which seasonally reached hypoxic to anoxic conditions. The origins of spawning are unknown, but the collection of eggs suggests that these low-velocity tributary habitats are used for spawning and are acceptable for survival, possibly even providing egg and larval refuge from predators. Eggs and larvae of target species, except Blueback Herring, were collected at the furthest upstream sampling location, which suggests that the dam was restricting upstream migration and habitat use. If the dam was to be removed or modified for fish passage, future studies could document how these species utilize and separate into the upstream habitats that once served as historical habitats for these species. Climate change and associated sea level rise, combined with habitat restriction from the dam, may affect how these species utilize the lower Tar River as time moves forward.

Atlantic sturgeon Acipenser oxyrinchus Mitchill, 1815 seasonal marine depth and temperature occupancy and movement in the Bay of Fundy

“…A major component of the life history of many anadromous, estuarine and coastal marine fishes is that they occupy marine habitats and undertake migrations to feed, reproduce and maintain themselves in a physiologically acceptable environment (Leggett & Whitney, ; Quinn & Leggett, ). Habitat occupancy and movement is also influenced by species, age, sex and maturity (Dell'apa, Cudney‐Burch, Kimmel, & Rulifson, ; Erickson et al., ; Smith & Rulifson, ). In the marine environment of the Bay of Fundy (BoF) fishes tend to move inshore to shallow habitats during summer, and offshore to deeper and seasonally warmer habitats during winter (Campana et al., ; Dadswell, Melvin, Williams, & Themelis, ; MacDonald, Dadswell, Appy, Melvin, & Methven, ; McCracken, ).…”

Species coexistence and niche interaction between sympatric giant panda and Chinese red panda: A spatiotemporal approach

“…A few patches are highly isolated, and the suitable habitats of giant pandas are more fragmented and less connected. It is necessary to strengthen the restoration of fragmented habitats and connectivity management for the protection of rare animals such as giant pandas and Chinese red pandas, which will help to increase the suitable habitats for giant pandas and Chinese red pandas and promote the spread and exchange of individuals (Haddad et al, 2015; Smith & Rulifson, 2015; Wang, Winkler, et al, 2021). We suggest to formulate corresponding protection measures according to the habitat distribution of each species and the preference of environmental factors, and then promote the protection of multiple species, so as to achieve the comprehensive protection and management of more species distributed in the same region, and optimize the umbrella effect on other species while protecting giant pandas.…”