Source audit: winter dens and fish mercury

Checked October 1, 2026. Scope: two existing story pages; shared search, place, map, and index metadata were left for the parent integration pass.

`pine-snake-hibernacula-long-study`

The 2015 Burger–Zappalorti paper supports the 120 known-age snakes, 23% always philopatric, and differences by age, sex, and site. Rutgers publication record; full-text record.
The linked long-term study is Burger and colleagues (2012), Journal of Herpetology 46:596–601, DOI 10.1670/11-100. Its author-hosted proof PDF has blank journal fields and a later URL file name; those do not establish a 2013 publication date. Corrected the page’s citation and source note.
The proof reports seven intensively monitored hibernacula over 1986–2011. An unoccupied den was used the next year in 22 of 58 observed den-years (37%); gaps sometimes reached ten years. These data are repeated observations at selected, excavated research dens, some with reconstructed chambers, and are not a random estimate for all Pine Barrens dens. Added that sampling context and kept den locations undisclosed.

NJDEP’s July 2002 research summary, archived by the New Jersey State Library, reports 258 samples from 30 water bodies in the 1996–97 survey. It says that survey included northern Pinelands waters, while the 1992–93 survey focused mainly on southern sites. Added those details.
The summary finds higher levels most often in predatory fish, but also reports that some commonly eaten lower-trophic fish exceeded then-used advisory thresholds. Added this without turning historic results into present-day consumption advice.
The report states that pH, alkalinity, conductivity, and dissolved organic carbon were interrelated, and it could not isolate their causal roles. Qualified the chemistry paragraph accordingly. Its two survey periods cannot establish a temporal trend.
NJDEP’s environmental trends page was available through indexed search text but direct retrieval returned a server error. The page’s 1972–2018, species-group comparison, and sample-size/sex caveats were confirmed through indexed text, not direct page inspection. The specimen-level laboratory data were not independently reviewed.

Update the snake entry’s search/index summary if it should mention the 2012 publication and selected-den study design. Keep its map precision broad; the authors intentionally withheld den locations because of collection risk.
The mercury entry’s 1992–2018 period reflects the main survey story, while the trends assessment includes earlier records dating to 1972. If the shared search metadata intends to span all cited observations, change it to 1972–2018; otherwise leave the period and clarify that the later assessment draws on earlier records.