Vulnerability of sea turtles and fishes in response to two catastrophic Caribbean hurricanes, Irma and Maria

J K Matley,R S Nemeth,S Eanes,P D Jobsis

doi:10.1038/s41598-019-50523-3

Abstract

Extreme weather events (e.g., cyclones, floods, droughts) are capable of changing ecosystems and altering how animals obtain resources. Understanding the behavioural responses of animals being impacted by these natural events can help initiate and ameliorate conservation or management programs. This study investigated short- and long-term space-use of the critically endangered hawksbill sea turtle (Eretmochelys imbricata), as well as five species of fishes and stingrays, in response to two of the most destructive Caribbean hurricanes in known history – Irma and Maria, which were at their peak intensity when they passed the US Virgin Islands in September of 2017. Using passive acoustic telemetry in St. Thomas, US Virgin Islands, we show a variety of short-term behavioural patterns initiated across species to reduce exposure to the strong environmental conditions, such as moving to deeper habitats within the study area. Although short-term expansion of activity space was evident for several sea turtles, long-term impacts on space-use and body condition were limited. In contrast, southern stingrays (Hypanus americanus) left the study area shortly after the hurricanes, suggesting vulnerability stemming from altered habitat, prey availability, or temperature/oxygen profiles. This study shows the strong spatial resilience of several nearshore species despite exposure to two consecutive category 5 hurricanes.

Highlights

Extreme weather events have the capacity to severely damage or disrupt ecosystems across a gradient of spatial and temporal scales[1]
In this paper we describe the results of an acoustic telemetry study, located in Brewers Bay, St
Standardized space-use sizes across individuals were relatively consistent throughout the detection period (Fig. 4), based on presence of outliers it was evident that several turtles (i.e., 1261, 1262, 1263) occupied larger core-use (50% autocorrelated kernel density estimates (AKDEs)) and extent areas (95% AKDEs) during the week after Hurricane Irma, as well as the week prior to Hurricane Irma (50% AKDEs: 1259, 1264, 15785) compared to most other weeks

Summary

Introduction

Extreme weather events have the capacity to severely damage or disrupt ecosystems across a gradient of spatial and temporal scales[1]. If deleterious conditions persist or respite from the disturbance is not attained, impacts may become more critical affecting survival through metabolic/nutritional deficiencies, disease, or phenotypic/genotypic selective pressures, among others[6,7,8] Overall, these consequences can alter population or community dynamics causing multiplicative effects throughout the ecosystem[9]. Predicting how animals will respond to or are affected by extreme weather provides relevant context for disaster planning and the ecological impacts that ensue This is especially applicable for management in areas that rely directly on access to natural resources for social or economic subsistence[22,23] (e.g., tourism, fishing, and agriculture). Long-term impacts were expected to be minimal except for those individuals that were driven outside Brewers Bay due to the hurricanes to find more suitable habitat

Methods

Results

Discussion

Conclusion