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 twelve surveys conducted during Summer 2016 through Spring 2019. 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. Information on the WEA surveys may be found in the second interim report.
There was some variation in sampling effort among surveys as a different camera system that captured a larger footprint was used after the Summer 2016 survey. Across all surveys, 98% of images contained no target species groups, vessels, or structures. Less than 2% of images contained target taxonomic groups. During the twelve surveys, biota included
- 76 species of birds
- 15 species of sharks
- 9 species of dolphins
- 9 species of whales
- 4 species of sea turtles
- 6 species of rays
- 3 species of seals
Some seasonal patterns were evident. In the Summer surveys, ray encounters were the most frequent, with the next most frequently encountered groups being birds, marine mammals, sharks, and turtles. During the Fall surveys bird encounters were the most frequent, followed by marine mammals. The Winter surveys were also dominated by birds followed by marine mammals. In the Spring surveys, birds still mostly dominated the sample, and there was a higher proportion of marine mammals, but the Spring 2018 survey was quite different, with sharks, mostly spurdogs, representing most of the sample followed by birds. No bats were found in imagery.
Avian species composition and abundance varied throughout the year and between years, highlighting not only the seasonal nature of avian activity, but also the interannual variation that can be expected. The Summer surveys were dominated by storm-petrels and shearwaters. The Fall 2016 survey was dominated by gulls and gannets, the Fall 2017 survey by phalaropes and gulls, and the Fall 2018 survey by gulls and phalaropes. Winter 2016–2017 was dominated by auks, gulls and gannets, and Winter 2017–2018 by shorebirds and gulls, and Winter 2018–2019 by gulls and ducks. Spring 2017 was dominated by Sterna terns and gulls, Spring 2018 was dominated by phalaropes and ducks, and Spring 2019 by gulls and storm-petrels.
Spatial patterns in bird abundance were apparent for some taxonomic groups, but absent for others. Black-capped petrels and Audubon’s shearwaters showed no substantial differences in distribution among the seasons, but both species clustered near the shelf break and in the northeast corner of the OPA. Sooty shearwaters were found primarily in the northeast corner of the OPA and near the shelf break, and in the western portion of the OPA at depth shallower than 70 m. Cory’s shearwaters showed a tendency to cluster in the northeast corner of the OPA, with fewer observations dispersed along the eastern edge. Great shearwaters were more evenly distributed across the OPA across all surveys, showing no particular preferences although Fall surveys clustered just to the north of the Hudson Canyon. Northern gannets also showed little spatial preference, although encounters were sparser in the central and eastern area of the OPA.
Herring gulls were found near shore in the Summer and widely distributed during the rest of the seasons and showing concentrations near the shelf break and in the Hudson Canyon area. Laughing gulls were found clustered nearer shore and there were no laughing gull observations in the Winter surveys. Blacklegged kittiwakes, ring-billed gulls, Bonaparte’s gulls, and small unidentified gulls were fairly evenly distributed. Great black-backed gulls were closer to shore during the Summer surveys, concentrated in the northeast and southeast portions of the OPA during the Fall and Winter surveys, and more widely dispersed during the Spring surveys, with some concentration on the shelf break.
Nearshore tendencies for least and royal terns were evident in the Summer and Spring surveys and black terns were more offshore. Other terns including Sterna tern species also showed nearshore preferences in the Summer and Spring surveys but also occurred throughout the OPA with some roseate terns found past the shelf break.
Sea ducks such as scoter species and long-tailed ducks were recorded primarily during the Fall and Winter surveys. With few exceptions, most observations were found nearshore.
Loons were mainly recorded during the Fall, Winter, and Spring while being almost absent during the Summer. Although loons showed some preference for nearshore areas, many observations were distributed across a wide bathymetric gradient with common loons showing denser aggregations in the southern and western OPA.
Phalaropes were found in all seasons although they were rarely found in the Summer and Winter surveys. In general, they were found beyond the 60 m isobath.
The dominant flight direction for most bird species groups was from west-to-east and east-to-west; although, ducks showed a more south-to-north trend. Across all seasons, 60% of birds were recorded sitting on the water, 11% were observed flying in the rotor-swept zone (RSZ), and 11% were observed above or below the RSZ; flight height could not be calculated for the remaining 18% of individuals.
Although population-sensitive species were distributed across the OPA, timing of aggregations varied with some spatial concentrations in the northeastern section during Summer 2016 and less so in the Summer 2017 and 2018 surveys. Population-sensitive species during the Fall and Winter were sparse, although more population sensitivity is apparent near shore in the Winter, and in the Fall and Spring appears to be more scattered. There was higher collision sensitivity evident in the Fall than other seasons. There were few collision-sensitive species in the Summer surveys. Displacement-sensitive species were found primarily near shore throughout the year, although during the Fall 2018 they were much denser in the northeast portion of the OPA, and in the Spring 2018 survey, aggregations were generally dense in the coastal and central portions of the OPA.
Turtles were most frequently observed in the Summer surveys with 97% of the observations occurring during this season. Loggerhead turtles were the most frequently found representing 74% of the total observations. Most turtles observed during the Summer, along with leatherback turtles observed during the Fall, occurred 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.
Seals were difficult to identify to the species level with 13% identified to species. Gray, harp and harbor seals were identified. Data were too sparse to define any patterns of activity for seals.
Dolphins were the most abundant of the marine mammals consisting of 97% of the observations followed by 1% whales and 1% seals; unidentified mammals consisted of 1.5% of the total mammal observations and based on size, these animals were dolphins or seals. Dolphins were abundant in all seasons, particularly in Spring and Summer surveys. Except for unidentified dolphins, common dolphin was the most abundant species in all but one seasonal survey; in the Summer 2016 survey had more Risso’s dolphin encounters. 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.
Fin whales were the most abundant species during the Summer, Fall and Winter 2017–2018 surveys, while common minke whales were the most abundant species during the Winter 2016–2017 and Spring surveys. Humpback whales had the same relative abundance as common minke whales in Spring 2017 and 2019 but were outnumbered by minke and sei whales in the Spring 2018 survey. North Atlantic right whales were present in the Winter 2016–2017 and Spring 2017 surveys. Sperm whales were observed in the Summer 2017, Summer 2018, Fall 2016, Fall 2018, and Winter 2018–2019 surveys. 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 mostly occurred during the Summer and Fall surveys with one ray observed in the Spring 2019 survey, and >99% of observations occurred in the Summer surveys. Cownose, bullnose, and cownose/bullnose rays were the most abundant with 85% of the total observations. Cownose and cownose/bullnose rays were most frequent in the northwestern portion of the OPA, while unidentified rays were found throughout the OPA. Devil rays and manta rays were concentrated along the shelf break. Travel direction for rays showed some preference for a WNW to ESE direction in the Summer surveys.
The majority (88%) of shark observations occurred during the Spring 2018 survey. The remaining shark observations were mainly in the Summer surveys across the OPA. Only blue sharks, basking sharks, white shark, scalloped hammerhead, smooth hammerhead, and tiger sharks were observed along with other unidentified species during the Fall surveys. In the Winter surveys, only basking shark, white shark, blue shark and spurdog were found. There were no spatial patterns of shark distributions evident in the OPA. Travel direction was highly variable but showed some WNW and ESE tendencies in the Summer 2017 survey.
Sixteen positively identified threatened and/or endangered species were recorded within the OPA during the 12 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). More than 68% of listed species observations occurred in Summer surveys and 30% occurred in spring surveys. Both of these seasonal surveys were dominated by numbers of Sterna terns and loggerhead turtles. Roseate terns identified to species comprised only 0.7% of observations (n=33).
Results from aerial high-resolution surveys can provide insight into spatial and temporal animal distributions within a surveyed area. Data from these surveys can 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.