andybeet
commented
9 months ago refernces to add to zotero and add to issue
- [x] Andrews and Mott 1967;
- [x] Lelli et al. 2009
- [x] Wood et al. 2022
Open BBeltz1 opened 1 year ago
andybeet
commented
9 months ago refernces to add to zotero and add to issue
sgaichas
commented
9 months ago Added Andrews and Mott 1967 Gray seals at Nantucket, Massachusetts: andrews_gray_1967 Lelli et al 2009 Seal Bounties in Maine and Massachusetts, 1888 to 1962: lelli_seal_2009 Wood et al 2022 Rates if increase in gray seal NEFSC Ref Doc: wood_gray_2022
Primary Contact
debra.palka@noaa.gov
Secondary Contact
No response
Data Name (This will be the displayed title in Catalog)
Gray Seal Pups
Indicator Name (as exists in ecodata)
seal_pups
Family (Which group is this indicator associated with?)
Data Description
The data presented here are counts of gray seal pups at 4 U.S. haulout sites from 1988 to 2021.
Introduction to Indicator (Please explain your indicator)
Gray seals were extirpated from the northeast U.S. coast by the mid-20th century due to local and statewide bounty systems [@andrews_gray_1967; @lelli_seal_2009]. Since the late 1980s, ground and aerial surveys have documented the recovery and recolonization of pupping sites in northeast U.S. waters [@wood_gray_2022]. This recovery is due in large part to the protection provided by the Marine Mammal Protection Act (MMPA) of 1972.
Key Results and Visualization
The increase in bycatch of gray seals (Fig. x) since 1995 corresponds to an increase in numbers of gray seals in U.S. waters, which has risen dramatically in the last three decades. Based on a survey conducted in 2021, the size of the gray seal population in the U.S. during the breeding season was approximately 28,000 animals, while in Canada the population was estimated to be roughly 425,000. The population in Canada is increasing at roughly 4% per year, and contributing to rates of increase in the U.S., where the number of pupping sites has increased from one in 1988 to nine in 2019. Mean rates of increase in the number of pups born at various times since 1988 at four of the more data-rich pupping sites (Muskeget, Monomoy, Seal, and Green Islands) ranged from no change on Green Island to high rates of increase on the other three islands, with a maximum increase of 26.3% (95%CI: 21.6 - 31.4%; @wood_rates_2020 Fig. x).
Implications
These high rates of increase in gray seal pups born at US pupping sites provide further support for the hypothesis that seals from Canada are continually supplementing the breeding population in U.S. waters.
Spatial Scale
Haul out sites off New England (Maine to New York) that correspond roughly to EPU’s Gulf of Maine (GOM) and Mid-Atlantic Bight (MAB).
Temporal Scale
Annually 1988 to 1921. Survey is in January that corresponds to the gray seal pupping season.
Synthesis Theme
Define Variables
1) Name=Year. 2) Name=Count; Definition=count of gray seals on haulout site; unit=n=number. 3) Name=colony; Definition=name of haul site site.
Indicator Category
If other, please specify indicator category
No response
Data Contributors
Stephanie Wood; Elizabeth Josephson
Point(s) of Contact
Stephanie Wood (Stephanie.Wood@noaa.gov), Elizabeth Josephson (elizabeth.josephson@noaa.gov), Kristin Precoda (Kristin.Precoda@noaa.gov)
Affiliation
NEFSC
Public Availability
Source data are NOT publicly available.
Accessibility and Constraints
Reach out to Stephanie Wood (stephanie.wood@noaa.gov) for data.