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 ten surveys conducted during Summer 2016 through Fall 2018. 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 first ten 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. In the Summer surveys, after rays, the most frequently encountered groups were birds, marine mammals, sharks, and turtles. During the Fall surveys bird encounters were the most frequent, followed by marine mammals. The Winter 2016–2017 and Winter 2017–2018 surveys were also dominated by birds followed by marine mammals. In the Spring 2017 surveys, birds still dominated the sample, and there was a higher proportion of marine mammals, but the Spring 2018 survey was quite different, with sharks representing most of the sample followed by birds. No bats were found in imagery.
Bird species composition and abundance varied throughout the year and between years. 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 by gulls and phalaropes. Winter 2016–2017 was dominated by auks, gulls and gannets, and Winter 2017–2018 by shorebirds, gulls, and ducks. Spring 2017 was dominated by Sterna terns and gulls, whereas Spring 2018 was dominated by phalaropes, ducks, and gulls.
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 also in the northeast corner of the OPA and near the shelf break in the Summer surveys, NYSERDA Digital Aerial Baseline Survey of Marine Wildlife in Support of Offshore Wind Energy Summer 2016–Fall 2018 Fifth Interim Report xiii and Cory’s shearwaters also showed a tendency to cluster in the northeast corner of the OPA, with fewer observations in the Fall dispersed along the eastern edge of the OPA and a more southward shift in distribution in the Spring 2017 survey. Gull observations occurred throughout the OPA, but most gull species showed nearshore tendencies in the Spring surveys. Black-legged kittiwakes, Bonaparte’s gulls and small unidentified gulls were fairly evenly distributed. 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 surveys but also occurred throughout the OPA with some roseate terns found past the shelf break. Scoter species and long-tailed duck were primarily found nearshore at shallower water depths. Phalaropes were generally 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, 69% of birds were recorded sitting on the water, 11% were observed flying in the rotor-swept zone (RSZ), and 8% were observed above or below the RSZ; flight height could not be calculated for the remaining 12% of individuals. There were no spatial preferences evident for flight heights, with species above and below the RSZ being evenly distributed across the OPA.
Although population-sensitive bird species were distributed across the OPA, timing of aggregations varied with some spatial concentrations in the northeastern section during Summer 2016, less so in the Summer 2017 and nearer shore in the Summer 2018 surveys. Population-sensitive species during the Fall and Winter surveys were sparse although some nearshore sensitivity was evident in the Winter 20162017 surveys. Collision-sensitive bird species were few in the Summer surveys, mostly occurring nearshore. However, they occurred throughout the OPA during other seasons. There were some collisionsensitive species nearer shore and near the shelf in the Fall 2016 and Fall 2018 surveys, less so in the Fall 2017 survey, and in the Winter surveys the Winter 2016–2017 survey showed more collision sensitivity farther from shore and nearer the shelf, whereas there was very little collision sensitivity in the Winter 2017–2018 survey. Displacement-sensitive species were found primarily near shore throughout the year, although the Fall 2018 aggregations were dense in the northeast portions of the OPA and Spring 2018 showed greater densities both nearshore and in the central area of the OPA.
Turtles were most frequently observed in the Summer surveys with 97% of the observations 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 west-to-east and east-to-west direction.
Seals were difficult to identify to the species level with 15% identified to species. Gray, harp and harbor seals were identified. Data were too sparse to define any patterns of activity for seals.
Fin whales were the most abundant species during the 2016 and 2017 Summer and Fall surveys and the Winter 2017–2018 survey, while common minke whales were the most abundant species during the Winter 2016–2017, Spring 2017 and 2018, and Summer 2018 surveys. Humpback whales had the same relative abundance as common minke whales in Spring 2017 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. 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.
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 2% of the total mammal observations and based on size, most of 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 a W and WNW to E and ESE direction and an ESE to WNW direction across most seasons, with more variability evident in the Winter 2017–2018 survey.
Rays only occurred during the Summer and Fall surveys, and >99% of observations occurred in the Summer surveys. Cownose and cownose/bullnose rays were the most abundant with 84% 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 (90%) 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, tiger sharks, hammerhead (unid.), and unknown shark species were observed during the Fall surveys. There were no spatial patterns of shark distributions evident in the OPA. The Summer 2018 was remarkable for its record number of spurdogs, with a corrected abundance of 319,984 individuals. Travel direction was highly variable but showed some WNW and ESE tendencies in the Summer 2017 survey.
Sixteen positively identified threatened or endangered species were recorded within the OPA during the first ten surveys. 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). Summer surveys recorded over 69% of listed species observations, followed by Spring surveys representing 28% of observations. Both of these seasonal surveys were dominated by numbers of Sterna terns and loggerhead turtles. Roseate terns identified to species comprised only 0.3% of observations (n=16).
Results from high-resolution aerial 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.