Whale sharks attract large numbers of tourists, divers and snorkelers each year to South Ari Atoll in the Republic of Maldives. Yet without information regarding the use and economic extent of the attraction, it is difficult to prioritize conservation or implement effective management plans. We used empirical recreational data and generalized mixed statistical models to conduct the first economic valuation (with direct spend as the primary proxy) of whale shark tourism in Maldives. We estimated that direct expenditures for whale shark focused tourism in the South Ari Marine Protected Area for 2012 and 2013 accounted for US$7.6 and $9.4 million respectively. These expenditures are based on an estimate of 72,000-78,000 tourists who are involved in whale shark excursions annually. That substantial amount of income to resort owners and operators, and tourism businesses in a relatively small area highlights the need to implement regulations and management that safeguard the sustainability of the industry through ensuring guest satisfaction and whale shark conservation.
The shifting baseline syndrome describes a gradual lowering of human cognitive baselines, as each generation accepts a lower standard of resource abundance or size as the new norm. There is strong empirical evidence of declining trends of abundance and body sizes of marine fish species reported from docks and markets. We asked whether these widespread trends in shrinking marine fish are detectable in popular English-language media, or whether news writers, like many marine stakeholders, are captive to shifting baselines. We collected 266 English-language news articles, printed between 1869 and 2015, which featured headlines that used a superlative adjective, such as "giant", "huge" or "monster", to describe an individual fish caught. We combined the reported sizes of the captured fish with information on maximum species-specific recorded sizes to reconstruct trends of relative size (reported size divided by maximum size) of newsworthy fishes over time. There was no evidence that relative length or relative weight declined over time either for the overall dataset, or for most subgroups of ecologically similar species (e.g., pelagic gamefish, oceanic sharks), or was linked to risk of extinction, which would have been consistent with a shifting baseline syndrome. However, 'charismatic megafish' (e.g., basking sharks, whale sharks, manta rays) did show a significant decline in the relative size of newsworthy fish over time, reflecting real biological shifts. While landing any individual of the large-bodied 'megafish' in this group may be newsworthy in part because of their large size relative to other fish species, the 'megafish' covered in our dataset were small relative to their own species -on average only 56% of the species-specific maximum length. The continued use in the English-language media of superlatives to describe fish that are now a fraction of the maximum size they could reach, or a fraction of the size they used to be, does reflect a shifting baseline for some species. Given that media outlets are a powerful tool for shaping public perception and awareness of environmental issues, there is a real concern that such stories might be interpreted as meaning that superlatively large fish still abound.PeerJ reviewing PDF | Manuscript to be reviewed 33 Abstract 34 35 The shifting baseline syndrome describes a gradual lowering of human cognitive baselines, as each 36 generation accepts a lower standard of resource abundance or size as the new norm. There is strong 37 empirical evidence of declining trends of abundance and body sizes of marine fish species reported from 38 docks and markets. We asked whether these widespread trends in shrinking marine fish are detectable in 39 popular English-language media, or whether news writers, like many marine stakeholders, are captive to 40 shifting baselines. We collected 266 English-language news articles, printed between 1869 and 2015, 41 which featured headlines that used a superlative adjective, such as "giant", "huge" or "monster", to 42 describe an individual fis...
Diagnosing the dangerous demography of manta rays using life history theory Background The directed harvest and global trade in the gill plates of mantas, and devil rays, has led to increased fishing pressure and steep population declines in some locations. The slow life history, particularly of the manta rays, is cited as a key reason why such species have little capacity to withstand directed fisheries. Here, we place their life history and demography within the context of other sharks and rays. Methods Despite the limited availability of data, we use life history theory and comparative analysis to estimate the intrinsic risk of extinction (as indexed by the maximum intrinsic rate of population increase r max) for a typical generic manta ray using a variant of the classic Euler-Lotka demographic model. This model requires only three traits to calculate the maximum intrinsic population growth rate r max : von Bertalanffy growth rate, annual pup production and age at maturity. To account for the uncertainty in life history parameters, we created plausible parameter ranges and propagate these uncertainties through the model to calculate a distribution of the plausible range of r max values. Results The maximum population growth rate r max of manta ray is most sensitive to the length of the reproductive cycle, and the median r max of 0.116 year-1 (CI: 0.089-0.139) is one of the lowest known of the 106 sharks and rays for which we have comparable demographic information. Discussion In common with other unprotected, unmanaged, high-value large-bodied sharks and rays this combination of very low population growth rates of manta rays, combined with the high value of their gill rakers and the international nature of trade, is highly likely to lead to rapid depletion and local extinction unless a rapid conservation management response occurs worldwide. Furthermore, we show that it is possible to derive important insights into the demography extinction risk of data-poor species using well-established life history theory.
The shifting baseline syndrome describes a gradual lowering of human cognitive baselines, as each generation accepts a lower standard of resource abundance or size as the new norm. There is strong empirical evidence of declining trends of abundance and body sizes of marine fish species reported from docks and markets. We asked whether these widespread trends in shrinking marine fish are detectable in popular English-language media, or whether news writers, like many marine stakeholders, are captive to shifting baselines. We collected 266 English-language news articles, printed between 1869 and 2015, which featured headlines that used a superlative adjective, such as "giant", "huge" or "monster", to describe an individual fish caught. We combined the reported sizes of the captured fish with information on maximum species-specific recorded sizes to reconstruct trends of relative size (reported size divided by maximum size) of newsworthy fishes over time. There was no evidence that relative length or relative weight declined over time either for the overall dataset, or for most subgroups of ecologically similar species (e.g., pelagic gamefish, oceanic sharks), or was linked to risk of extinction, which would have been consistent with a shifting baseline syndrome. However, 'charismatic megafish' (e.g., basking sharks, whale sharks, manta rays) did show a significant decline in the relative size of newsworthy fish over time, reflecting real biological shifts. While landing any individual of the large-bodied 'megafish' in this group may be newsworthy in part because of their large size relative to other fish species, the 'megafish' covered in our dataset were small relative to their own species -on average only 56% of the species-specific maximum length. The continued use in the English-language media of superlatives to describe fish that are now a fraction of the maximum size they could reach, or a fraction of the size they used to be, does reflect a shifting baseline for some species. Given that media outlets are a powerful tool for shaping public perception and awareness of environmental issues, there is a real concern that such stories might be interpreted as meaning that superlatively large fish still abound.PeerJ reviewing PDF | Manuscript to be reviewed 33 Abstract 34 35 The shifting baseline syndrome describes a gradual lowering of human cognitive baselines, as each 36 generation accepts a lower standard of resource abundance or size as the new norm. There is strong 37 empirical evidence of declining trends of abundance and body sizes of marine fish species reported from 38 docks and markets. We asked whether these widespread trends in shrinking marine fish are detectable in 39 popular English-language media, or whether news writers, like many marine stakeholders, are captive to 40 shifting baselines. We collected 266 English-language news articles, printed between 1869 and 2015, 41 which featured headlines that used a superlative adjective, such as "giant", "huge" or "monster", to 42 describe an individual fis...
Despite the promise of hematological parameters and blood chemistry in monitoring the health of marine fishes, baseline data is often lacking for small fishes that comprise central roles in marine food webs. This study establishes blood chemistry and hematological baseline parameters for the pinfish Lagodon rhomboides, a small marine teleost is among the most dominant members of near-shore estuarine communities of the Atlantic Ocean and Gulf of Mexico. Given their prominence, pinfishes are an ideal candidate species to use as a model for monitoring changes across a wide range of near-shore marine communities. However, pinfishes exhibit substantial morphological differences associated with a preference for feeding in primarily sea-grass or sand dominated habitats, suggesting that differences in the foraging ecology of individuals could confound health assessments. Here we collect both baseline data on the blood physiology of pinfish while assessing the relationship between blood parameters and measured aspects of feeding morphology using data collected from 37 individual fishes. Our findings provide new baseline health data for this important near shore fish species and find no evidence for a strong linkage between blood physiology and either sex or measured aspects of feeding morphology. Comparing our hematological and biochemical data to published results from other marine teleost species suggests that analyses of trends in blood value variation correlated with major evolutionary transitions in ecology will shed new light on the physiological changes that underlie the successful diversification of fishes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.