River dolphins are among the world's most seriously endangered species, and the baiji (Lipotes vexillifer), endemic to the Yangtze River, China, is likely to become extinct in the near future. Here we review the status of the obligate river dolphins (baiji, bhulan, Platanista minor, susu, Platanista gangetica, and boto, Inia geoffrensis), discuss the threats they face, and present recommendations for their conservation. River dolphins are particularly vulnerable to the activities of humans because of their restricted habitat. Threats vary geographically in their importance, but generally include accidental killing during fishing operations, depletion of prey from over-exploitation, and habitat loss and population fragmentation from water development. Deliberate killing for dolphin products also threatens the animals in some areas. Recommendations include (among others) the following: (i) establishing meaningful protected areas, (ii) raising public awareness on the ecological and cultural value of river dolphins, (iii) training local workers in conservation techniques, (iv) managing fisheries to reduce accidental killing and ensure the sustainability of prey, and (v) adopting conservation strategies that incorporate the ecological integrity of riverine environments.Key words: River dolphins, Platanista, Lipotes, Inia, Orcaella, Neophocaena, Sotalia, water development, river ecosystems.
A newly discovered molluscan fauna provides an approximate age for a previously undated gravel sequence capping Nose Hill, a relict plateau adjacent to the Bow River in Calgary, Alberta, and constrains the age of the physiographic relief in the area. The fauna consists of a mixed terrestrial-aquatic assemblage whose composition indicates a paleoclimatic regime similar to that of the area today. The fossiliferous sediment, interpreted as a pond deposit, is a pebbly mud within a thick braid-plain gravel sequence. Isoleucine epimerization in the molluscs is not inconsistent with an Early Pleistocene or older age for the deposit. The Nose Hill gravels and an equivalent sequence capping another outlier (Broadcast Hill) located on the other side of the Bow River define an originally extensive paleuplains surface. Fluvial dissection of the surface, including 175 mof incision by the Bow River and resultant separation of the two outliers, occurred within the last one to two million years.Une faune de mollusques, trouvte r k m m e n t , fournit un Ige approximatif B la skquence de gravier non datk qui coiffe la colline Nose, un plateau rtsiduel adjacent B larivibre Bow dans Calgary, Alberta, et parconsCquent impose un Ige limite au relief physiographique dkveloppt dans cette rtgion. La faune inclut une association formte d'un mklange d'origines terrestre et aquatique, qui indique un rCgime palCoclimatique analogue i celui qui existe aujourd'hui dans cette rtgion. Le stdiment fossilifere, interprktk comme un dtpbt d'ttang, est une boue caillouteuse associke i une sauence de gravier dans une vaste plaine anastomoske. L'tpimtrisation de l'isoleucine dans les mollusques n'est pas incompatible avec un Ige pltistocbne prtcoce ou plus ancien pour le dCpBt. Les graviers de la colline Nose et une skquence Cquivalente qui coiffe une autre butte-ttmoin (la colline Broadcast), localiske de l'autre cbtt de la rivikre Bow, dkfinissent ce qui Ctait initialement une aire de palto-plaines Ctendue. L'trosion fluviale de l'aire, incluant une incision de 175 m creuste par la rivikre Bow, et la stparation des deux buttes-ttmoins qui s'ensuivit, sont apparues durant le demier ou les deux derniers millions d'annkes.[Traduit par la rtdaction]Can.
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.