First insights into the movements of young-of-the-year white sharks (Carcharodon carcharias) in the western North Atlantic Ocean

Tobey H Curtis,Brett Mcbride,Leann J Winn,Jessica Quinlan,Gregory Metzger,Christopher Fischer,Matthew J Ajemian,Michael Mccallister

doi:10.1038/s41598-018-29180-5

Abstract

In recent years, white sharks (Carcharodon carcharias) have become more accessible to researchers off the northeastern U.S. as feeding aggregation sites have emerged and the population has increased. However, there has been limited research on young-of-the-year (YOY) sharks relative to older age classes in this region. Previous research indicated that YOY white sharks were most frequently observed in the New York Bight, suggesting the region serves a nursery role. To further examine the species’ use of this area, we deployed satellite and acoustic tags on ten YOY white sharks (138–166 cm total length) off Long Island, New York. The sharks remained resident in New York Bight waters through summer (August through October), further supporting the notion that the region is a nursery area. Southward movements were observed during fall, with overwintering habitat identified off North and South Carolina shelf waters. Return migrations toward the New York Bight were observed in some individuals the following spring. YOY white sharks in this heavily-populated region are exposed to anthropogenic impacts such as fisheries bycatch and coastal habitat degradation. As juvenile survival rates are important for long-term population sustainability, further research is necessary to assess the potential impacts of these activities on the western North Atlantic white shark population.

Highlights

White sharks (Carcharodon carcharias) have not been as well studied in the western North Atlantic Ocean as they have in other regions of their circumglobal range[1,2,3,4]
Minimal research has been conducted on young-of-the-year (YOY) white sharks in the western North Atlantic as this age class has not been predictably accessible to researchers over the years[4,5]
A single Argos position was received from WS6 after a period of six days post-release and it was not detected on the Atlantic Cooperative Telemetry (ACT) network

Summary

Introduction

White sharks (Carcharodon carcharias) have not been as well studied in the western North Atlantic Ocean as they have in other regions of their circumglobal range[1,2,3,4]. Data on individual movements and residency patterns would help address this criterion and confirm if the New York Bight, or other areas in the western North Atlantic, serve as white shark nursery areas[8]. Despite the long-term knowledge of YOY white shark presence in the New York Bight, to date, there have been no focused field studies on the species, and many basic questions about their distribution, movements, and habitat use in this region remain unanswered. White sharks are prohibited (no-retention) species in the U.S Atlantic[9]; they are incidentally captured in a number of rod and reel, trawl, gillnet, longline, and trap/weir fisheries and subject to occasional bycatch mortality[4] Due to their smaller size and nearshore distribution, YOY white sharks are comparatively susceptible to bycatch[4,10,11,12]. This represents the first time YOY white sharks have been tracked in the North Atlantic, and provides novel insights into the spatial ecology of this life stage that complement recent work on larger white sharks[7]

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