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  • Thumbnail for The local aspects of marine resource management : a case study of two small-scale fisheries in Costa Rica
    The local aspects of marine resource management : a case study of two small-scale fisheries in Costa Rica by Gillett, Nicole Valerie

    The world’s fisheries provide humans with a significant source of protein and are the backbone of many coastal communities’ livelihoods. They are crucial for healthy marine ecosystems and biodiversity. Yet despite this they have been an ever worsening state for years. Marine resource management theories and techniques have attempted to address this crisis yet fish stocks continue to decline. One sector of the marine resource management, which is frequently underappreciated, are the small-scale fisheries which sustain millions of people worldwide and are negatively impacted by these decreasing trends. This study took place in two small-scale fishing communities along the Pacific Coast of Costa Rica. Both study sites are near marine conservation sites; however the one effort is a locally initiated Responsible Fishing Area and one is a government run Marine National Park. The studies focused on the perceptions of local fishermen and community members on the state of marine resources, conservation, and their role in resource management. Overall, correlations were found between increased community involvement in local marine management areas and more positive perceptions and investment, in the success of the area. These results add to past studies and new management theories which call for an increase in local participation and inclusion in management and marine conservation efforts in order to harness the support of these communities and address the needs of those people who depend on marine resources.

  • Thumbnail for The effects of a habitat fragmentation gradient on species richness and activity of insectivorous bats in Costa Rica
    The effects of a habitat fragmentation gradient on species richness and activity of insectivorous bats in Costa Rica by Cormier, Amanda

    Bats are the most species richness mammalian order in the tropics. Throughout the world, bats comprise 25% of mammalian species and this percentage increases to over half along the equator. The large ecological impact of bats, through insect control and pollination for example, is related to their species diversity and abundance in the tropics. Because of this large impact, it is important to study the effects of habitat fragmentation gradient including agriculture on these bat populations. I examined the differences in insectivorous bat species diversity and activity in the habitat gradient between the tropical rainforest in Tirimbina Biological Reserve in La Virgen de Sarapiquí, Heredia, Costa Rica and the nearby organic pineapple farm, Finca Corsicana. I hypothesized a decrease in species richness and activity with an increase in human disturbance from the forest, to the edge of the forest, to the pineapple farm (activity is defined as the number of passes per minute). I also predicted that the different bat families would show a difference in habitat preferences due to the habitat specialist versus generalist classification system, which includes their distinct flight and eating patterns. Finally, I expected a difference in species diversity and activity throughout the night and a variation between collection days. Over four weeks in March and April 2013, I placed ultrasonic recorders at 12 different sites to pick up the bats’ calls. I then analyzed the recordings to identify the species. I found four families and 22 different species of bats. The results showed a significant decrease in the number of bat passes (the number of times a bat passes the recorder per minute) in the pineapple farm, in comparison to the edge, and the forest. Along with this main conclusion of all bat species, the Emballonuridae foraged mostly in the edge habitats, the Molossidae were spread out between the edge and forest, and the Vespertilionidae were found evenly among all three habitats. There was not a significant difference in bat activity through out the night, however there was a significant difference in the mean number of passes per week and per day. Overall, my results suggest that maintaining forest and edge habitats are important to maintaining species richness of bats in tropical rainforests.

  • Thumbnail for Bird communities in an agroforest ecosystem in Costa Rica : an underappreciated conservation resource
    Bird communities in an agroforest ecosystem in Costa Rica : an underappreciated conservation resource by Greenler, Skye McClure

    Tropical conservation and research has focused primarily on protected areas and has largely neglected the conservation value of the vast and growing agricultural areas. Understanding how species and groups of species persist in deforested areas and react to conversion of tropical rainforest to agricultural land is critical to maximize conservation. I compared bird community composition in four habitats in a mixed agriculture- tropical rainforest ecosystem in Northeastern Costa Rica: organic shade-grown cacao plantation, live fences in silvopasture, riparian forests in a silvopasture matrix, and preserved late successional forest. Point counts over two-months (March-April, 2013) found 167 species from 35 families. Detrended correspondence analysis showed that all three agroforest habitats and the rainforest each sustain a different assemblage of birds, indicating that the varied agricultural landscape in this area supports a higher species richness of birds than any of the individual systems would on their own. Mean number of species identified per point was greatest in live fences, intermediate in riparian forest and cacao , and lowest in the rainforest. New world warblers and the nectar, small insects/spiders diet guild were more abundant in cacao; flycatchers, sparrows, and the ground foraging strata were more abundant in live fences; ovenbirds and omnivores were more abundant in riparian forest; and wrens and the fruits or fruits and seeds diet guild were more abundant rainforest. Many bird species in the agricultural lands occurred only in the shade trees of the cacao plantation, only in the live fences within the pastures, and only in the riparian forest buffers. Given this, legislation and management should continue to require and encourage preserving the forested aspects of the agricultural landscape. To provide maximum large landscape conservation, a varied agricultural landscape must be maintained outside of preserves to promote maximum avian diversity and take advantage of the considerable conservation benefits of many agricultural systems.