Effects of increased salinity on tadpoles of two anurans from a Caribbean coastal wetland in relation to their natural abundance

2008 ◽  
Vol 29 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Neftalí Rios-López

Abstract Many amphibians depend on wetland ecosystems for reproduction and survival, and coastal wetlands are not the exception. Recent advances on climate change research predict a reduction in land cover of coastal wetlands due to sea-level rise in response to global warming. Although this scenario will contribute to further amphibian population declines worldwide the impacts of sea-level rise and its related salt water intrusion on anuran assemblages in coastal wetlands remain largely unknown. I documented patterns of abundance of the native Caribbean white-lipped frog (Leptodactylus albilabris) and the introduced marine toad (Bufo marinus) along an inland-to-coastal salinity gradient in Puerto Rico. In addition, I investigated the effects of increasing salinity on larval growth and survival to metamorphosis in L. albilabris and B. marinus in laboratory experiments. In the field, relative abundance of adults of L. albilabris decreased with increasing salinity, while B. marinus showed the opposite pattern. Laboratory experiments with L. albilabris and B. marinus revealed that percentage of larvae surviving to metamorphosis in both species was greatly reduced in 22-25% seawater (8 ppt), which is within salinity levels found in their natural distribution. In this salinity level, the native L. albilabris showed ∼100% metamorphosis failure while the introduced B. marinus showed ∼60% metamorphosis failure. The reduction in metamorphosis was due to high mortality in L. albilabris and was accompanied with morphological abnormalities in B. marinus. Tadpoles of only L. albilabris reared for four weeks showed significant weight loss at 8 ppt, but showed no difference in length. These results suggest that anuran tadpoles may be living near their physiological limit for salinity in the studied wetland. Conservation implications are profound, however, as salt water intrusion and urban encroaching inland may result in anuran population replacement, from native species to introduced species in this wetland.

2016 ◽  
Author(s):  
Karin Ebert ◽  
Karin Ekstedt ◽  
Jerker Jarsjö

Abstract. Future sea level rise as a consequence of global warming will affect the world's coastal regions. Even though the pace of sea level rise is not clear, the consequences will be severe and global. Commonly the effects of future sea level rise are investigated for relatively vulnerable development countries; however, a whole range of varying regions need to be considered in order to improve the understanding of global consequences. In this paper we investigate consequences of future sea level rise along the coast of the Baltic Sea island of Gotland, Sweden, with the aim to fill knowledge gaps regarding comparatively well-suited areas in non-development countries. We study both the quantity of loss of infrastructure, cultural and natural values for the case of a two metre sea level rise of the Baltic Sea, and the effects of climate change on seawater intrusion in coastal aquifers, causing the indirect effect of salt water intrusion in wells. We conduct a multi-criteria risk analysis by using Lidar data on land elevation and GIS-vulnerability mapping, which gives formerly unimaginable precision in the application of distance and elevation parameters. We find that in case of a 2 m sea level rise, 3 % of the land area of Gotland, corresponding to 99 km2, will be inundated. The features most strongly affected are items of touristic or nature values, including camping places, shore meadows, sea stack areas, and endangered plants and species habitats. In total, 231 out of 7354 wells will be directly inundated, and the number of wells in the high-risk zone for saltwater intrusion in wells will increase considerably. Some values will be irreversibly lost due to e.g. inundation of sea stacks and the passing of tipping points for sea water intrusion into coastal aquifers; others might simply be moved further inland, but this requires considerable economic means and prioritization. With nature tourism being one of the main income sources of Gotland, monitoring and planning is required to meet the changes. Seeing Gotland in a global perspective, this island shows that holistic multi-feature studies of future consequences of sea level rise are required, to identify overall consequences for individual regions.


2017 ◽  
Vol 14 (2) ◽  
pp. 251-255 ◽  
Author(s):  
B. Bhowmick ◽  
Z. Uddin ◽  
S. Rahman

Salinity intrusion greatly affects the livelihood decisions which farmers have to make. Both environmental and anthropogenic factors affect salt water intrusion within south west Bangladesh. Although climate change and sea level rise are thought to increase salinity, siltation and sedimentation of canals reduces access to surface water and prevents salt water intrusion in to farming zones. This study highlights how decreasing salinity within Khulna and Bagerhat districts is allowing farmers to diversify their agricultural practices, reducing vulnerability and improving household income and food security. By using both quantitative and qualitative data collection, semi structured interviews were held with farmers and landless people to understand how they adapt to salinity changes. The results show that whilst salinity decreases were identical across both districts, farmers adapt to the changes in a number of ways based primarily on their access to water. Whilst shrimp production struggles to improve, increases in freshwater production of prawns, fin fish and dyke crops partially confirm that salinity was decreasing within the area. Furthermore, increases in income generation were also observed confirming that diversification improved rural livelihoods. In the wider context, understanding farmer mitigation strategies towards the environment allows for future comparisons to be made on climate change and sea level rise which are widely considered to drive salt water intrusion further in land.


2001 ◽  
Vol 9 ◽  
pp. 229-236
Author(s):  
Yoshinobu TABUCHI ◽  
Kiyoshi TAKIKAWA ◽  
Kentaro MINOMO ◽  
Masao KIDA

2019 ◽  
Author(s):  
Adam T Carpenter

Sea Level Rise poses a substantial concern to communities worldwide. Increased inundation, storm surge, salt water intrusion, and other impacts create challenges which will require considerable planning to address. Recognizing the broad and differing scope of sea level rise issues and the variability of policy options to address them, local planning frameworks are necessary in addition to tools and resources available from state and federal governments. To help assess priorities and preferences on sea level rise planning, a survey of 503 persons affiliated with coastal communities on the East Coast of the United States was conducted in December 2017. This survey studied key aspects locally-driven sea level rise plans, including planning priorities, funding options, methods to resolve conflict, and potential responses. Six key findings address these and other concerns to provide the foundation of a locally driven framework for public officials.


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