Abstract
In support of New York State’s commitment to incorporating offshore wind into its energy portfolio, the New York State Energy Research and Development Authority (NYSERDA) embarked on a multi-year ultra-high resolution aerial digital survey of marine resources in a 43,745.20 km2, (12,754.06 mi2) offshore planning area (OPA) in 2016. The OPA encompasses the waters of the New York Bight from Long Island southeast to the continental shelf break. Surveys are conducted on a quarterly basis, timed to coincide with periods of abundance of avian and marine species that could be vulnerable to impacts from offshore wind activities. This report summarizes the results of the first year of surveys conducted Summer 2016 through Spring 2017. Each survey collected images covering at least 7% of the OPA.
For each survey, approximately 300,000 images were collected within the OPA using a transect design. During the first survey year, special attention was also paid to the wind energy area (WEA) using a more detailed grid survey design, collecting around 100,000 images. Each survey collected images covering at least 10% of the WEA.
There was some variation in sampling effort between surveys as a different camera system was used after the Summer 2016 survey. Across all surveys, >96% of images did not contain any target species groups, vessels, or structures. Less than 4% of images contained target taxonomic groups. During the first year, biota included 55 species of birds, 13 species of sharks, 8 species of dolphins, 5 species of whales, 4 species of sea turtles, 3 species of rays, and 3 species of seals. Some seasonal patterns were evident. During the Summer survey, the vast majority of the organisms observed were rays (8,331 images) or birds (1,869 images). During the Fall, Winter, and Spring surveys, birds predominated, appearing in 12,352, 20,958, and 3,807 images, respectively.
Bird abundance varied widely across seasons with shearwaters and storm-petrels being dominant in the Summer, gulls and gannets dominant in the Fall, auks most abundant in Winter, and Sterna terns and gulls most abundant during the Spring. Spatial patterns in bird abundance were apparent for some taxonomic groups, but absent for others. Cory’s shearwaters tended to cluster in the northeast corner of the OPA, while sooty shearwater was found primarily in the southern portion of the OPA. Gull observations occurred throughout the OPA, but some concentrations were found nearshore. Royal terns and least terns were primarily observed nearshore while black terns were primarily observed >50 km offshore. Scoter species and long-tailed duck were primarily found nearshore. Phalaropes were generally found beyond the ≈60-m isobath.
The dominate flight direction for auks, fulmars, gannets, gulls, loons, phalaropes, shearwater, and storm petrels was from west-to-east and east-to-west; no directional trends were evident for other species groups. Across all seasons, 72% of birds were recorded sitting on the water, 11% were observed flying in the rotor-swept zone (RSZ), and 7% were observed above or below the RSZ; flight height could not be calculated for the remaining 10% of individuals. Sensitivity indices showed that collision-sensitive species occurred most often nearshore and along the western edge of the OPA. Displacement-sensitive species were most numerous in Winter and were found in the central and eastern portions of the OPA. Population-sensitive species most often congregated in the northeastern portion of the OPA in Summer and Winter, but this trend was not apparent in the other seasons.
Turtles were most frequently observed in the Summer with 93% of the observations occurring during this season. Loggerhead turtles were the most frequently found representing 64% of the total observations. Most turtles observed during the Summer, along with leatherback turtles observed during the Fall, occurred in inside the 70-m isobath. Outside these findings, there were no obvious spatial patterns among species or seasons. Turtle travel direction followed primarily a WNW to ESE direction.
Dolphins were the most abundant of the marine mammals consisting of 95% of the observations followed by 1% seals and 1% whales; unidentified mammals consisted of 3% of the total mammal observations. Dolphins were abundant in all seasons, particularly in Spring. With the exception of unidentified dolphins, common dolphin was the most abundant species in all seasons with 34% of the total dolphin observations. Pilot whale, Risso’s dolphin, striped dolphin, Atlantic white-sided dolphin, Atlantic spotted dolphin, and rough-toothed dolphin all showed a definite preference for deeper water at the shelf break throughout the year. Dolphins were most frequently traveling in an ESE to WNW direction.
Seals were difficult to identify to the species level and 88% of seals were classified as unknown. Of the seals that could be classified at the species level, gray seals were the most abundant with 8% of the observations.
Whales occurred during all seasons and fin whales were the most abundant overall with 28% of the observations. Whales showed a preference for the shelf break, although fin, humpback, minke, and north Atlantic right whales were also found elsewhere in the OPA. No spatial distribution patterns by season were evident. Whales were most frequently traveling in an ESE to WNW direction.
Rays only occurred during the Summer and Fall, and >99% of observations occurred in the Summer. Cownose and cownose/bullnose rays were the most abundant with 82% of the total observations. Ray observations identified to species were most frequent in the northwestern portion of the OPA, while unidentified rays were found throughout the OPA. Giant manta rays were concentrated along the shelf break. Travel direction was highly variable for rays and showed no distinct patterns.
The majority of shark observations (79%) were not classified to the species level. Most shark observations occurred during the Summer and Spring with 97% of observations occurring during these seasons. There were no spatial patterns of shark distributions evident in the OPA. Travel direction was highly variable and showed no patterns within or among seasons. Thirteen threatened and endangered species were recorded within the OPA during the first year of surveys not including species groups that may include listed species. Our categorization of threatened and endangered species was conservative and included species groups: “Sterna tern” (possibly representing roseate tern), “hammerhead shark (unid.)” (possibly representing scalloped hammerhead), and “turtle species unknown” (possibly representing all endangered turtles). Over 97% of listed species observations occurred in the Summer and Spring, which was driven by numbers of Sterna terns and loggerhead turtles.
Results from aerial high-resolution surveys can provide insight into spatial and temporal animal distributions within a surveyed area. Data from these surveys can be used to inform wind turbine siting decisions at a high-level and site-level through better understanding of species composition, relative abundance, and animal movements. This information can also be used in developing project-specific environmental documents such as Environmental Assessments and Environmental Impact Statements should the need arise.