Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Aug 28;5(3):20.
doi: 10.3390/toxics5030020.

Metal Levels in Blood of Three Species of Shorebirds during Stopover on Delaware Bay Reflect Levels in Their Food, Horseshoe Crab Eggs

Joanna Burger  1   2 , Nellie Tsipoura  3 , Michael Gochfeld  4   5
Affiliations

Metal Levels in Blood of Three Species of Shorebirds during Stopover on Delaware Bay Reflect Levels in Their Food, Horseshoe Crab Eggs

Joanna Burger et al. Toxics. .

Abstract

Understanding the relationship between metal level in predators and their prey is an important issue, and is usually difficult to determine because animals eat a variety of organisms. However, shorebirds that stop over during spring migration along Delaware Bay (New Jersey) stay for only 2-3 weeks, and eat mainly horseshoe crab (Limulus polyphemus) eggs. In this paper, we examine the relationship between metal levels in horseshoe crab eggs, and blood and feather levels of metals in red knot (Calidris canutus rufa; n = 30), sanderling (Calidris alba; n = 20) and semipalmated sandpiper (Calidris pusilla; n = 38) from Delaware Bay. There is a rich literature on metal levels in feathers. For all three species, the levels of arsenic, cadmium, chromium, lead and mercury in blood were highly correlated with the levels of metals in the eggs of horseshoe crab (17 pooled samples). This indicates that the levels in the blood of these shorebirds quickly reflect levels in their prey (horseshoe crab eggs), while metals in the feathers were not correlated with the levels in eggs. Semipalmated sandpipers had the lowest levels of arsenic in blood and the highest levels of arsenic in feathers, compared to the other species. At Delaware Bay, semipalmated sandpipers have a diet higher in marsh invertebrates than the other species, which may account for the differences. The levels of cadmium and chromium in blood were significantly higher in knots than other species; knots only ate horseshoe crab eggs. For all of the metals except arsenic, the ratio of levels in blood/feathers was similar among species. For arsenic, the ratio of levels in blood/feathers were significantly lower in semipalmated sandpipers than in the other species, by an order of magnitude.

Keywords: Limulus polyphemus; arsenic; blood; cadmium; chromium; feathers; horseshoe crab eggs; lead; mercury; red knot; sanderling; sempalmated sandpiper; shorebirds.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Map showing location of collection of blood of shorebirds and the eggs of horseshoe crabs (see arrow) along Delaware Bay.
Figure 2
Figure 2
Relationship of mean levels of arsenic, cadmium, chromium, lead and mercury in the blood of three species of shorebirds and the mean level in eggs of horseshoe crabs, their primary prey while on migratory stopover in May at Delaware Bay, New Jersey. (See Table 1).
See this image and copyright information in PMC

References

    1. Nygard T., Lie E., Roy N., Steinnes E. Metal dynamics in an Antarctic food chain. Mar. Pollut. Bull. 2001;42:598–602. doi: 10.1016/S0025-326X(00)00206-X. - DOI - PubMed
    1. Kim J., Koo T.J. The use of feathers to monitor heavy metal contamination in herons, Korea. Arch. Environ. Contam. Toxicol. 2007;53:435–441. doi: 10.1007/s00244-006-0196-y. - DOI - PubMed
    1. Burger J., Gochfeld M. Habitat, Population Dynamics, and Metal Levels in Colonial Waterbirds: A Food Chain Approach. CRC Press; Boca Raton, FL, USA: 2016.
    1. Furness R.W., Rainbow P.S. Heavy Metals in the Marine Environment. CRC Press; Boca Raton, FL, USA: 1990.
    1. Burger J., Gochfeld M. Effects of chemicals and pollution on seabirds. In: Schreiber B.A., editor. Biology of Marine Birds. CRC Press; Boca Raton, FL, USA: 2001. pp. 485–576.