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  • 1
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    Unbekannt
    PANGAEA
    In:  Supplement to: Selgrath, Jennifer C; Roelfsema, Christiaan M; Gergel, Sarah E; Vincent, Amanda C J (2016): Mapping for coral reef conservation: comparing the value of participatory and remote sensing approaches. Ecosphere, 7(5), e01325, https://doi.org/10.1002/ecs2.1325
    Publikationsdatum: 2023-09-16
    Beschreibung: A mosaic of two WorldView-2 high resolution multispectral images (Acquisition dates: October 2010 and April 2012), in conjunction with field survey data, was used to create a habitat map of the Danajon Bank, Philippines (10°15'0'' N, 124°08'0'' E) using an object-based approach. To create the habitat map, we conducted benthic cover (seafloor) field surveys using two methods. Firstly, we undertook georeferenced point intercept transects (English et al., 1997). For ten sites we recorded habitat cover types at 1 m intervals on 10 m long transects (n= 2,070 points). Second, we conducted geo-referenced spot check surveys, by placing a viewing bucket in the water to estimate the percent cover benthic cover types (n = 2,357 points). Survey locations were chosen to cover a diverse and representative subset of habitats found in the Danajon Bank. The combination of methods was a compromise between the higher accuracy of point intercept transects and the larger sample area achievable through spot check surveys (Roelfsema and Phinn, 2008, doi:10.1117/12.804806). Object-based image analysis, using the field data as calibration data, was used to classify the image mosaic at each of the reef, geomorphic and benthic community levels. The benthic community level segregated the image into a total of 17 pure and mixed benthic classes.
    Schlagwort(e): Danajon_Bank; MULT; Multiple investigations; Philippines
    Materialart: Dataset
    Format: application/zip, 19.3 MBytes
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Environmental biology of fishes 44 (1995), S. 347-361 
    ISSN: 1573-5133
    Schlagwort(e): Syngnathidae ; Sex differences ; Entelurus aequoreus ; Nerophis ophidion ; Syngnathus ; Pisces
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Synopsis Synopsis Pipefishes have rarely been watched in the wild and have never before been followed in their common seagrass habitats. This study explores the reproductive ecology of five species of pipefishes living in a Swedish eelgrass meadow during parts of four breeding seasons, tagging four of the species. Pipefish are remarkable for their specialised paternal care: only males aerate, osmoregulate and nourish the developing embryos. Two of the species (Entelurus aequoreus andNerophis ophidion) have simple ventral gluing of eggs on the trunk while three species (Syngnathus acus, S. rostellatus andS. typhle) have fully enclosed brood pouches on their tails. Males of the former species receive eggs from one female while males of the genusSyngnathus receive partial clutches from several females. Sex ratios of adults on the site differed from equal to male-biased to female-biased, according to species.S. typhle were most numerous and were resighted most often. They were present throughout the breeding season whereas there were temporal shifts in the presence of the other species on the meadow and in some sex ratios. Most species occurred in the deeper, denser part of the meadow but there was some habitat separation by species and sex. All species tended to stay low in the eelgrass, primarily coming up above the eelgrass to display and mate. No species showed site fidelity either to a home range or to the meadow, withE. aequoreus adults spending least time on the meadow. Sexual size dimorphism differed: males were larger inS. rostellatus, the same size inS acus and smaller in the other species. Although the species overlap in habitat requirements and breeding season, the only observed interspecific interactions were abortive courtships betweenSyngnathus species.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
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    Unbekannt
    PANGAEA
    In:  EPIC3Bremerhaven, PANGAEA
    Publikationsdatum: 2016-09-05
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: PANGAEA Documentation , notRev
    Format: application/pdf
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
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    Unbekannt
    In:  http://aquaticcommons.org/id/eprint/15162 | 403 | 2014-05-29 07:20:15 | 15162 | United States National Marine Fisheries Service
    Publikationsdatum: 2021-07-03
    Beschreibung: Bycatch studies have largely ignored population level effects on fish species of little commercial interest. Here we analyze bycatch of the lined seahorse (Hippocampus erectus) in the bait-shrimp trawl fishery in Hernando Beach, Florida, providing the first fisheries data for this species. Based on catch per unit of effort (CPUE), size, sex, and reproductive status of trawled H. erectus, 1) approximately 72,000 seahorses were caught annually by this fleet, from a population of unknown size, 2) trawling affected population cohorts differentially because of temporal and spatial variation in CPUE and population size, and 3) a greater proportion of females than males was removed in trawling. Our findings suggest that trawling may affect seahorse populations through direct mortality, social disruption, and habitat damage. However, the lack of specific abundance or catchability estimates for H. erectus means that the precise impact of trawling on this fish remains uncertain. This paper focuses attention on the need for research and monitoring of small fishes that are caught incidentally in nonselective gear.
    Schlagwort(e): Fisheries ; Management
    Repository-Name: AquaDocs
    Materialart: article , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 721-731
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
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    Unbekannt
    Aquaculture Department, Southeast Asian Fisheries Development Center | Tigbauan, Iloilo, Philippines
    In:  http://aquaticcommons.org/id/eprint/26205 | 17342 | 2019-02-08 06:43:14 | 26205 | Southeast Asian Fisheries Development Center, Aquaculture Department
    Publikationsdatum: 2021-07-24
    Beschreibung: Seahorses (family Syngnathidae, genus Hippocampus) have set precedents globally. They were among the first marine fishes of commercial importance to be listed on both the IUCN Red List and CITES Appendix II. Overfishing and non-selective fishing are two agents in their depletion, so management is clearly needed. We here outline what is known about these fishes and their trade, before considering the potential role the culture and release could play in rebuilding wild populations.
    Schlagwort(e): Aquaculture ; Marine fish ; Marine fisheries ; Marine organisms ; Tropical fish ; Marine aquaculture ; Resource conservation ; Aquaculture economics ; Aquaculture development ; Stock assessment ; Stocks ; Depleted stocks ; Hippocampus barbouri ; Hippocampus erectus ; Hippocampus fisheri ; Hippocampus fuscus ; Hippocampus histrix ; Hippocampus ingens ; Hippocampus kuda ; Hippocampus mohneki ; Hippocampus reidi ; Hippocampus trimaculatus ; Hippocampus abdominalis ; Hippocampus breviceps ; Hippocampus capensis ; Hippocampus whitei ; Hippocampus zosterae ; Hippocampus guttulatus
    Repository-Name: AquaDocs
    Materialart: book_section
    Format: application/pdf
    Format: application/pdf
    Format: 71-84
    Format: 13
    Standort Signatur Einschränkungen Verfügbarkeit
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