Conservation hotspots for marine turtle nesting in the United States based on coastal development

Abstract

Coastal areas provide nesting habitat for marine turtles that is critical for the persistence of their populations. However, many coastal areas are highly affected by coastal development, which affects the reproductive success of marine turtles. Knowing the extent to which nesting areas are exposed to these threats is essential to guide management initiatives. This information is particularly important for coastal areas with both high nesting density and dense human development, a combination that is common in the United States. We assessed the extent to which nesting areas of the loggerhead (Caretta caretta), the green (Chelonia mydas), the Kemp's ridley (Lepidochelys kempii), and leatherback turtles (Dermochelys coriacea) in the continental United States are exposed to coastal development and identified conservation hotspots that currently have high reproductive importance and either face high exposure to coastal development (needing intervention), or have low exposure to coastal development, and are good candidates for continued and future protection. Night-time light, housing, and population density were used as proxies for coastal development and human disturbance. About 81.6% of nesting areas were exposed to housing and human population, and 97.8% were exposed to light pollution. Further, most (>65%) of the very high- and high-density nesting areas for each species/subpopulation, except for the Kemp's ridley, were exposed to coastal development. Forty-nine nesting sites were selected as conservation hotspots; of those high-density nesting sites, 49% were sites with no/low exposure to coastal development and the other 51% were exposed to high-density coastal development. Conservation strategies need to account for ~66.8% of all marine turtle nesting areas being on private land and for nesting sites being exposed to large numbers of seasonal residents.

Influences of the Local Climate on Loggerhead Hatchling Production in North Florida: Implications From Climate Change

“…Indeed, tropical nesting beaches in the Caribbean, Central America, and Australasia are projected to experience decreases in hatchling production throughout the 21st century due to projected climate change (Pike, 2014;Santidrián Tomillo et al, 2015;Hays et al, 2017). The variability in how hatchling production from temperate and tropical nesting beaches may be affected by climatic changes highlights the need for focused research and conservation initiatives on temperate nesting grounds as they may become future havens of successful reproductive output (Katselidis et al, 2012;Almpanidou et al, 2016;Fuentes et al, 2016).…”

Risk to North American Birds from Climate Change-Related Threats

“…Coastal habitats support large numbers of bird species in concentrated areas along shorelines, beaches, and tidal areas, and sea level rise is anticipated to increase erosion, shoreline retreat, and loss of coastal habitat [112][113][114]. In addition, coastal systems are increasingly faced with encroachment from coastal development and increased housing density, population growth, and disturbance [115]. The combination of habitat loss from inundation and erosion due to sea level rise, and coastal armoring to counteract these impacts, can lead to loss of roosting sites, lower species abundance and richness, and higher mortality and nest failures [25,112].…”

“…Additionally, wildfires may also become more frequent with increased human populations and encroachment on wild areas [116], further altering natural fire regimes and adding potential sources of ignition, a source of fire risk that we were unable to project in our analysis. For coastal systems, increased pressures from both urbanization, causing habitat loss inland [115,117], and climatedriven sea level rise, causing habitat loss from the oceans, may create a squeezing effect that accelerates decline in these systems. These examples highlight how researchers and managers can use threats analyses such as this one to more completely assess vulnerability and risk to species and habitats under climate change [11].…”

Novel Bio-Logging Tool for Studying Fine-Scale Behaviors of Marine Turtles in Response to Sound

“…Because the habitat use of marine turtles overlaps extensively with anthropogenic activities that produce sounds such as fishing, shipping, and coastal and marine development (Van Dolah and Maier, 1993;Wallace et al, 2010;Lewison et al, 2014;Fuentes et al, 2016) it is important to develop tools and techniques that enable us to examine how such activities affect the behavior and physiology of these threatened species. The case study presented here showcasing a successful deployment of a ROTAG on a juvenile green turtle provides proof of concept for using these tags to examine marine turtles in response to sound and demonstrates their utility in examining the general soundscapes of marine turtles.…”

“…We include a description of the ROTAG and demonstrate proof-of-concept via a case study of a successful deployment on a juvenile green turtle in the Paranaguá Estuarine Complex (PEC) off Paraná state in southern Brazil. Because the habitat use of marine turtles overlaps extensively with sound produced by anthropogenic activities such as fishing, shipping, and coastal and marine development (Van Dolah and Maier, 1993;Wallace et al, 2010;Lewison et al, 2014;Fuentes et al, 2016), the application of the ROTAG will enable researchers to gain important insights regarding how and to what extent such activities may affect marine turtles. This information is critically needed and can be used to aid in marine turtle conservation and management.…”