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1.
Nat Ecol Evol ; 8(6): 1118-1128, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38769434

ABSTRACT

Many shark populations are in decline around the world, with severe ecological and economic consequences. Fisheries management and marine protected areas (MPAs) have both been heralded as solutions. However, the effectiveness of MPAs alone is questionable, particularly for globally threatened sharks and rays ('elasmobranchs'), with little known about how fisheries management and MPAs interact to conserve these species. Here we use a dedicated global survey of coral reef elasmobranchs to assess 66 fully protected areas embedded within a range of fisheries management regimes across 36 countries. We show that conservation benefits were primarily for reef-associated sharks, which were twice as abundant in fully protected areas compared with areas open to fishing. Conservation benefits were greatest in large protected areas that incorporate distinct reefs. However, the same benefits were not evident for rays or wide-ranging sharks that are both economically and ecologically important while also threatened with extinction. We show that conservation benefits from fully protected areas are close to doubled when embedded within areas of effective fisheries management, highlighting the importance of a mixed management approach of both effective fisheries management and well-designed fully protected areas to conserve tropical elasmobranch assemblages globally.


Subject(s)
Conservation of Natural Resources , Coral Reefs , Fisheries , Sharks , Skates, Fish , Animals , Conservation of Natural Resources/methods
2.
Science ; 380(6650): 1155-1160, 2023 06 16.
Article in English | MEDLINE | ID: mdl-37319199

ABSTRACT

A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing diversity deficits in reef elasmobranch (shark and ray) assemblages. Our species-level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages. Shark-dominated assemblages persist in wealthy nations with strong governance and in highly protected areas, whereas poverty, weak governance, and a lack of shark management are associated with depauperate assemblages mainly composed of rays. Without action to address these diversity deficits, loss of ecological function and ecosystem services will increasingly affect human communities.


Subject(s)
Conservation of Natural Resources , Coral Reefs , Extinction, Biological , Sharks , Skates, Fish , Animals , Humans , Fisheries , Biodiversity
3.
Clin Case Rep ; 11(1): e6830, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36694655

ABSTRACT

We analyzed a tiger shark (estimated 2.8 m total length) bite on a snorkeler. The removal of the terminal part of the leg suggests a predatory motivation for the bite. This is the first documented bite by a tiger shark in French Polynesia waters for the past 75 years.

4.
J Forensic Sci ; 66(6): 2493-2498, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34418091

ABSTRACT

Understanding why sharks bite humans is essential for developing strategies to prevent these incidents. Here, we use bite wound characteristics and eye witness descriptions of shark behavior to determine the likely motivation for several bites perpetrated by an oceanic whitetip (OWT) shark Carcharhinus longimanus on an adult female snorkeler off Moorea island (French Polynesia) in October 2019. The victim was snorkeling with others in pelagic waters as part of an organized whale-watching tour when the shark-without any warning behavior-bit her at least three times resulting in severe injuries with substantial loss of soft tissue from the chest and both forearms. The victim survived these injuries thanks to rapid and effective first aid provided by her companions. The sudden, unprovoked and repeated bites with substantial tissue removal are consistent with predatory behavior although the dominance hypothesis cannot be fully ruled out. This would be the first case of a predatory shark bite ever documented in French Polynesia in over 70 years of data collection. Given the routine association of OWT sharks with cetaceans, in-water whale watching activities should adopt appropriate risk management strategies in regions hosting this species of shark.


Subject(s)
Bites and Stings/pathology , Predatory Behavior , Sharks , Animals , Female , Humans , Polynesia
5.
J Forensic Sci ; 65(3): 979-983, 2020 May.
Article in English | MEDLINE | ID: mdl-31670847

ABSTRACT

Identifying the species and size of sharks responsible for biting humans is essential for developing strategies to prevent these incidents. Here, we use bite wound characteristics and genetic analysis of a tooth fragment extracted from the wounds to identify a sicklefin lemon shark Negaprion acutidens as the perpetrator of nonfatal bites on the legs of an adult male surfer at Makemo atoll (French Polynesia) in January 2018. The bite was superficial, and N. acutidens are fish predators not known to feed on large prey; hence, foraging is an unlikely explanation for this incident rather linked to territoriality. Lemon sharks are occasionally aggressive toward humans and are site attached with relatively small home ranges; hence, avoiding surfing in the area of a previous bite incident is recommended to decrease the risk of future injuries.


Subject(s)
Bites and Stings/pathology , Sharks , Water Sports , Animals , Behavior, Animal , Bites and Stings/etiology , DNA/isolation & purification , DNA Fingerprinting , Electron Transport Complex IV/genetics , Humans , Male , Middle Aged , Polymerase Chain Reaction , Polynesia , Sequence Analysis, DNA , Sharks/genetics , Species Specificity , Tooth/chemistry
6.
J Fish Biol ; 95(2): 562-574, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31119738

ABSTRACT

Bonefishes Albula spp. are important components of subsistence fisheries and lucrative sport fishing industries throughout their circumtropical distribution. In Oceania, however, Albula spp. have historically been overexploited and there is a growing need to balance the demands of competing fishing sectors, making the description of their life history a regional priority. To this aim, we collected biological samples from Albula spp. of Anaa atoll, French Polynesia, to identify the species that compose the stock and estimate their life-history parameters including age, growth, reproduction and natural mortality. Our results indicate that Albula glossodonta is the species of bonefish present, with a maximum age that is below the, 20 year longevity of the genus (8 years in males and 10 years in females). Differential growth patterns existed between the two sexes (L∞ = 58, 78 cm fork length (LF ) and K = 0.38, 0.21 for males and females, respectively). Males attained sexual maturity at 43 cm LF (c. 3 years) whereas females matured at 48 cm LF (c. 4 years) and oocyte production was significantly related to body mass, with a maximum batch fecundity of 1,133,767 oocytes in a 4406 g (70 cm LF ) female. The gonado-somatic index of harvested fishes indicated that the spawning season extends from March through September. Based on the observation of a, 20 year bonefish at the proximate Tetiaroa Atoll and several empirical models, estimates of natural mortality ranged from 0.21 to 0.68; however, an estimate of 0.21 was deemed most appropriate. This information facilitated the resurgence of a Rahui (temporary fishing closure) and community-based management to protect A. glossodonta during a critical portion of their spawning season and in this context our results provide an important demographic baseline in evaluating the recovery of this fishery.


Subject(s)
Fishes/physiology , Life History Traits , Animals , Female , Fertility , Fisheries , Longevity , Male , Oceania , Oocytes , Reproduction , Seasons
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