Latest Articles from Nature Conservation Latest 2 Articles from Nature Conservation https://natureconservation.pensoft.net/ Fri, 29 Mar 2024 14:14:02 +0200 Pensoft FeedCreator https://natureconservation.pensoft.net/i/logo.jpg Latest Articles from Nature Conservation https://natureconservation.pensoft.net/ Applying bayesian population assessment models to artisanal, multispecies fisheries in the Northern Mokran Sea, Iran https://natureconservation.pensoft.net/article/25212/ Nature Conservation 28: 61-89

DOI: 10.3897/natureconservation.28.25212

Authors: Abdul Rashid Jamnia, Ahmad Ali Keikha, Mahmoud Ahmadpour, Abdoul Ahad Cissé, Mohammad Rokouei

Abstract: Small-scale fisheries substantially contribute to the reduction of poverty, local economies and food safety in many countries. However, limited and low-quality catches and effort data for small-scale fisheries complicate the stock assessment and management. Bayesian modelling has been advocated when assessing fisheries with limited data. Specifically, Bayesian models can incorporate information of the multiple sources, improve precision in the stock assessments and provide specific levels of uncertainty for estimating the relevant parameters. In this study, therefore, the state-space Bayesian generalised surplus production models will be used in order to estimate the stock status of fourteen Demersal fish species targeted by small-scale fisheries in Sistan and Baluchestan, Iran. The model was estimated using Markov chain Monte Carlo (MCMC) and Gibbs Sampling. Model parameter estimates were evaluated by the formal convergence and stationarity diagnostic tests, indicating convergence and accuracy. They were also aligned with existing parameter estimates for fourteen species of the other locations. This suggests model reliability and demonstrates the utility of Bayesian models. According to estimated fisheries’ management reference points, all assessed fish stocks appear to be overfished. Overfishing considered, the current fisheries management strategies for the small-scale fisheries may need some adjustments to warrant the long-term viability of the fisheries.

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Research Article Mon, 13 Aug 2018 14:49:19 +0300
Effects of forest fragmentation on the morphological and genetic structure of a dispersal-limited, endangered bird species https://natureconservation.pensoft.net/article/10905/ Nature Conservation 16: 39-58

DOI: 10.3897/natureconservation.16.10905

Authors: Claudia Hermes, Annika Döpper, H. Martin Schaefer, Gernot Segelbacher

Abstract: Throughout the tropics, pristine forests disappear at an alarming pace. This presents a severe threat to forest-dependent species. Especially dispersal-limited understory birds are affected by forest loss. We here explored the effects of habitat fragmentation on the genetic structure and the morphology of the Ecuadorian Tapaculo (Scytalopus robbinsi). This bird occurs only in a small range in the premontane cloud forests of southwestern Ecuador. The global population size is declining rapidly due to habitat loss and is currently estimated at only 3000 mature individuals. We caught a total of 28 Ecuadorian Tapaculos in forests of varying size in an area of about 40 km². From each bird, we took morphological measurements and a blood sample. This was used to develop a set of 10 species-specific microsatellite primers for genetic analysis and we found that the Ecuadorian Tapaculos display high levels of genetic diversity. Additionally, we identified dispersal corridors for the species across the landscape using a least-cost path analysis. Notably, we found that wing shape is related to forest size. Individuals in smaller fragments show adaptations of the wing morphology to enhanced mobility and better flight capacity. Our results suggest that the Ecuadorian Tapaculo may rapidly adapt its morphology to the level of habitat fragmentation. This potential can possibly mitigate the risk of local extinctions of the species due to human-caused forest loss and fragmentation.

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Research Article Fri, 25 Nov 2016 11:26:11 +0200