scholarly journals Feeding habitats of juvenile reef fishes in a tropical mangrove–seagrass continuum along a Malaysian shallow-water coastal lagoon

2020 ◽  
Vol 96 (3) ◽  
pp. 469-486
Author(s):  
Dung Quang Le ◽  
Siau Yin Fui ◽  
Kentaro Tanaka ◽  
Suhaimi Suratman ◽  
Yuji Sano ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Habitat Use ◽  
Anthropogenic Activities ◽  
Fish Habitat ◽  
Reef Fishes ◽  
Epinephelus Coioides ◽  
Gut Content ◽  
Isotopic Tracers ◽  
Seagrass Meadows ◽  
Nursery Habitats

We conducted stable isotope (δ13C and δ15N) and gut content analyses to understand habitat use of juvenile reef fishes (Lethrinus lentjan, Lutjanus russellii, and Epinephelus coioides), particularly the influence of spatial habitat structure along seagrass–mangrove continua. Sampling was conducted in Setiu Lagoon, located in the southern waters of the South China Sea (Malaysia). Gut content analysis indicated that the focal fishes preyed mainly on benthic invertebrates and other smaller fishes; these were used as potential prey items for isotopic tracers to track fish habitat use. Stable isotope analyses highlighted that the juvenile reef fishes were highly associated with seagrass beds as feeding grounds; however, site-specific analyses suggest differences in fish feeding habitats. The juvenile fishes, particularly large juveniles, preyed in both mangrove and seagrass areas from the central lagoon, whereas all juveniles showed preferential foraging within seagrass meadows in the nearby lagoon mouth. Furthermore, the mean stable isotope values of muscle tissue differed among fish size classes, indicating their ontogenetic habitat/diet shifts, especially for L. lentjan and E. coioides. This study provides important information to support current efforts in protecting and preserving mangroves and seagrasses as crucial nursery habitats for juvenile reef fishes from the anthropogenic activities influencing Setiu Lagoon.

scholarly journals Site fidelity, vertical movement, and habitat use of nearshore reef fishes on offshore petroleum platforms in southern California

2019 ◽  
Vol 95 (4) ◽  
pp. 657-682 ◽  
Author(s):  
Carlos Mireles ◽  
Christopher JB Martin ◽  
Christopher G Lowe
Keyword(s):  
Habitat Use ◽  
Site Fidelity ◽  
Fish Habitat ◽  
Reef Fishes ◽  
Vertical Movement ◽  
San Pedro ◽  
Ecological Importance ◽  
Bottom Depth ◽  
Petroleum Platforms ◽  
Offshore Petroleum

Off California, economically important nearshore reef fishes inhabit the shallow (<20 m) regions of offshore petroleum platforms on the San Pedro Shelf (SPS). It is essential to understand the degrees to which platforms support fish over time to indicate whether biological requirements (e.g., shelter, diet, reproduction) are being met. To determine the ecological importance of platforms as fish habitat, the site fidelity and depth/habitat use of adult cabezon, Scorpaenichthys marmoratus (Ayres, 1854), grass rockfish, Sebastes rastrelliger (Jordan and Gilbert, 1880), kelp rockfish, Sebastes atrovirens (Jordan and Gilbert, 1880), and California sheephead, Semicossyphus pulcher (Ayres, 1854) were investigated at platforms Edith (50 m bottom depth) and Eureka (212 m). A total of 63 fish were acoustically tagged and monitored for up to 578 d. Sixty-three percent of individuals were still present at platforms at the end of the study (long-term site fidelity), with 55 individuals detected a mean of 66.9% (SD 36.0%) of their total days at liberty (daily site fidelity). All species displayed a shift in seasonal depth use. The shallowest horizontal level, consisting of various horizontal beams at platform Edith (15 m depth) and Eureka (17 m), was the most utilized habitat by grass rockfish, kelp rockfish, and California sheephead. Cabezon at platform Eureka utilized depths (21–31 m) unassociated with horizontal levels, while at platform Edith they primarily utilized the second horizontal level (30 m). Decommissioning options that remove the shallowest 26 m of structure would eliminate the habitat most utilized by three of the four study species that dominate the nearshore reef fish communities at SPS platforms.

Modeling cetacean habitat use in an urban coastal area in southeastern Brazil

2020 ◽  
Vol 642 ◽  
pp. 227-240
Author(s):  
L Lodi ◽  
R Tardin ◽  
G Maricato
Keyword(s):  
Habitat Use ◽  
Protected Areas ◽  
Linear Models ◽  
Anthropogenic Activities ◽  
Buffer Zone ◽  
Humpback Whales ◽  
Southeastern Brazil ◽  
Major Influence ◽  
Cetacean Species ◽  
Few Data

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.

scholarly journals A forensic approach to understanding diet and habitat use from stable isotope analysis of (avian) claw material

2003 ◽  
Vol 17 (2) ◽  
pp. 270-275 ◽  
Author(s):  
S. Bearhop ◽  
R. W. Furness ◽  
G. M. Hilton ◽  
S. C. Votier ◽  
S. Waldron
Keyword(s):  
Stable Isotope ◽  
Habitat Use ◽  
Stable Isotope Analysis ◽  
Isotope Analysis

scholarly journals Fish densities associated with structural elements of oil and gas platforms in southern California

2019 ◽  
Vol 95 (4) ◽  
pp. 639-656 ◽  
Author(s):  
Erin L Meyer-Gutbrod ◽  
Li Kui ◽  
Mary M Nishimoto ◽  
Milton S Love ◽  
Donna M Schroeder ◽  
...  
Keyword(s):  
Habitat Use ◽  
Southern California ◽  
Oil And Gas ◽  
Fish Assemblages ◽  
Fish Habitat ◽  
Artificial Reef ◽  
Offshore Structures ◽  
Structural Elements ◽  
Structural Element ◽  
Young Of The Year

There are thousands of offshore oil and gas platforms worldwide that will eventually become obsolete, and one popular decommissioning alternative is the "rigs to reefs" conversion that designates all or a portion of the underwater infrastructure as an artificial reef, thereby reducing the burden of infrastructure removal. The unique architecture of each platform may influence the size and structure of the associated fish assemblage if different structural elements form distinct habitats for fishes. Using scuba survey data from 11 southern California platforms from 1995 to 2000, we examined fish assemblages associated with structural elements of the structure, including the major horizontal crossbeams outside of the jacket, vertical jacket legs, and horizontal crossbeams that span the jacket interior. Patterns of habitat association were examined among three depth zones: shallow (<16.8 m), midwater (16.8–26 m), and deep (>26 m); and between two life stages: young- of-the-year and non-young-of-the-year. Fish densities tended to be greatest along horizontal beams spanning the jacket interior, relative to either horizontal or vertical beams along the jacket exterior, indicating that the position of the habitat within the overall structure is an important characteristic affecting fish habitat use. Fish densities were also higher in transects centered directly over a vertical or horizontal beam relative to transects that did not contain a structural element. These results contribute to the understanding of fish habitat use on existing artificial reefs, and can inform platform decommissioning decisions as well as the design of new offshore structures intended to increase fish production.

scholarly journals Lagoon Biogeochemical Processing is Reflected in Spatial Patterns of Sediment Stable Isotopic Ratios

2020 ◽  
Vol 8 (11) ◽  
pp. 874
Author(s):  
Elizabeth Burke Watson ◽  
Alejandro Hinojosa-Corona ◽  
Johannes R. Krause ◽  
Juan Carlos Herguera ◽  
Julianna McDonnell ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Spatial Patterns ◽  
Nitrogen Isotopes ◽  
Carbon Accumulation ◽  
Isotopic Ratios ◽  
Spatial Gradients ◽  
Seagrass Meadows ◽  
The Pacific ◽  
Stable Isotopic ◽  
Sediment Carbon

The spatial analysis of biota, particulate organic matter, and sediments for stable isotopes of carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) have proved useful for identifying patterns in productivity, nutrient pollution, and relationships between biological and physiochemical variables at the local and global scales. Yet such approaches are rarely applied to studies of lagoon or estuarine metabolism. Focusing on Bahía San Quintín, a heterotrophic seagrass-dominated lagoon on the Pacific coast of Baja California, México, we report on spatial patterns in surficial sediment CNS stable isotopic ratios as tracers of lagoon biogeochemical function. Stable nitrogen isotopes highlighted potential spatial variability in the balance between denitrification and nitrogen-fixation within the lagoon and identified an association between elevated δ15N levels and oyster culture, suggesting that oyster presence may be enhancing N2 production. Spatial patterns in δ34S covaried with sediment particle size, underlining the importance of sediment texture in determining the depth of sub-oxic-anoxic redox zones. Sediment carbon stable isotope ratios highlighted the lack of incorporation of seagrass carbon into seagrass meadow sediments, thus emphasizing the importance of phytoplankton or microphytobenthos for carbon accumulation in seagrass meadows. This report highlights the value of sediment isotopic values in corroborating spatial patterns in estuarine metabolism or macronutrient processing identified from chamber or flux-based studies. Stable isotope mapping can provide a useful addition to assessment of estuarine metabolism, or act as a stand-alone tool for generating hypotheses, identifying the influence of spatial gradients, and/or suggesting prime locations for investigation of microbial abundance or function.

Sign in / Sign up

Export Citation Format

Share Document