Coastal development has placed significant pressures on once pristine sandy beaches. Among other stresses, property owners often remove native vegetation and natural debris and replace (or displace) native species with non-native ornamentals. Non-native species can disrupt vegetative communities, pollination cycles, water use, nutrient transfer, and patterns of erosion. For example, Australian pines (Casuarina equisetifolia) often crowd-out native trees, palm trees can exacerbate wind erosion, and so on. These human-induced actions and reactions cause an overall reduction in available nesting habitat for sea turtles, and can significantly diminish the quality of the nesting habitat that remains.
Why is this important? Because the highly endangered hawksbill sea turtle prefers to nest within the shelter of woody vegetation. The loss of vegetation can mean that a female must crawl further onshore in search of suitably vegetated areas. Other sea turtle species prefer to nest on the open beach platform (seaward of vegetated areas), using the dark vegetation backdrop as an important ambient cue. After egg-laying is complete, vegetation can be important in safeguarding sea turtle nests by helping to maintain the natural beach structure, reducing compaction of sand grains, moderating diurnal temperature changes, and reducing erosion. Vegetation can also provide an aesthetically pleasing tool to reduce or block beachfront lighting that would otherwise discourage sea turtles from nesting or misdirect hatchlings away from the sea.
Coastal property owners should adopt certain standards and practices in regards to vegetation. First and foremost – strive to protect beachfront forest, and to restore native vegetation and natural habitat which has been lost. Become familiar with and utilize native trees and shrubs – including sea grape (Coccoloba uvifera), almond (Terminalia catappa) and portia (Thespesia populnea) trees, coco plum (Chysobalanus icaco), and so on – for landscaping purposes.
In general, native plants require less maintenance and save energy – planted properly, they require little or no extra water, fertilizer, or pesticides. In addition, they display resistance to insects and disease and often attract desirable wildlife including birds, butterflies, and pollinators. Identify source-books on locally occurring species, explore online resources such as Cayman Wildlife Connection's inventory of Native Trees and Seaside Plants, and establish partnerships with experts, including botanical gardens and nurseries.
Non-native plants, especially coconut palms (Cocos nucifera), should not be planted on or near beaches where sea turtles are likely to nest. Our experience confirms that palms provide insufficient cover for nesting, and their roots act as a hardened structure which solidifies habitat and may accelerate erosion (especially wind erosion) of the beach. Other non-native plants may create too much shade on the sand, which can alter nest temperature and affect the development (and sex ratio) of sea turtle embryos, or they may out-compete or displace important native species.
Remember to share your conservation efforts! Post signs that communicate to guests, clients and visitors the importance of coastal plantings and habitats, and describe any restrictions or conditionalities. Raised walkways can be very effective in guiding beachgoers to the shore while protecting fragile coastal areas. Visitors are likely to enjoy learning about historical uses (e.g., cultural, nutritional, medicinal) of native species – create a "nature walk" simply by posting botanical notes!
On Pasture Bay Beach (Jumby Bay) in Antigua, beachfront property owners have created "beach gardens" to provide nesting habitat to hawksbill sea turtles while maintaining an aesthetically beautiful landscape for the island owners and their resort guests. Native coastal plant species – including ink berry (Scaevola plumeria), sea-grape (Coccoloba uvifera), bay cedar (Suriana maritime), beach morning glory (Ipomoea pes-caprae), and sea bean (Canavalia maritime) – are planted in groupings on a nesting beach that had seen its beach forest diminished by development.
As the years have passed, there is clear evidence that the beach gardens are providing additional nesting habitat. However, the highest density of nesting still occurs in areas of the beach with remnants of intact native maritime forest. Therefore, while restoration efforts (e.g., beach gardens, reforestation) are important where habitat loss has already occurred, architects and property managers should always make every effort to preserve native maritime forest.