1. Kelp as a bioindicator: Does it matter which part of 5 m long plant is used for metal
analysis?
Burger, Joanna (1, 2); Gochfeld, Michael (2, 3); Jeitner, Christian (1, 2); Gray, Matt (1, 2); Shukla, Tara (2, 3); Shukla,
Sheila (1, 2); Burke, Sean (2, 4)
Source: Environmental Monitoring and Assessment, v 128, n 1-3, p 311-321, May 2007; ISSN: 01676369, E-ISSN:
15732959; DOI: 10.1007/s10661-006-9314-6; Publisher: Kluwer Academic Publishers
Author affiliation: (1) Division of Life Sciences, Rutgers University, Piscataway, NJ, United States (2) Environmental
and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers
University, Piscataway, NJ, United States (3) Environmental and Occupational Medicine, UMDNJ-Robert Wood
Johnson Medical School, Piscataway, NJ, United States (4) Memorial Sloan-Kettering Cancer Center, Kettering
Institute, 425 East 68th Street, New York, NY, United States
Abstract: Kelp may be useful as a bioindicator because they are primary producers that are eaten by higher trophic
level organisms, including people and livestock. Often when kelp or other algae species are used as bioindicators,
the whole organism is homogenized. However, some kelp can be over 25 m long from their holdfast to the tip of the
blade, making it important to understand how contaminant levels vary throughout the plant. We compared the levels
of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in five different parts of the kelp Alaria
nana to examine the variability of metal distribution. To be useful as a bioindicator, it is critical to know whether levels
are constant throughout the kelp, or which part is the highest accumulator. Kelp were collected on Adak Island in
the Aleutian Chain of Alaska from the Adak Harbor and Clam Cove, which opens onto the Bering Sea. In addition
to determining if the levels differ in different parts of the kelp, we wanted to determine whether there were locational
or size-related differences. Regression models indicated that between 14% and 43% of the variation in the levels of
arsenic, cadmium, chromium, manganese, mercury, and selenium was explained by total length, part of the plant,
and location (but not for lead). The main contributors to variability were length (for arsenic and selenium), location
(mercury), and part of the plant (for arsenic, cadmium, chromium and manganese). The higher levels of selenium
occurred at Clam Cove, while mercury was higher at the harbor. Where there was a significant difference among parts,
the holdfast had the highest levels, although the differences were not great. These data indicate that consistency
should be applied in selecting the part of kelp (and the length) to be used as a bioindicator. While any part of Alaria
could be collected for some metals, for arsenic, cadmium, chromium, and manganese a conversion should be made
among parts. In the Aleutians the holdfast can be perennial while the blade, whipped to pieces by winter wave action,
is regrown each year. Thus the holdfast may be used for longer-term exposure for arsenic, cadmium, chromium and
manganese, while the blade can be used for short-term exposure for all metals. Cadmium, lead and selenium were
at levels that suggest that predators, including people, may be at risk from consuming Alaria. More attention should
be devoted to heavy metal levels in kelp and other algae from Adak, particularly where they may play a role in a
subsistence diets. © Springer Science+Business Media B.V. 2007. (68 refs)
Main heading: Biomarkers
Controlled terms: Algae - Marine biology - Mathematical models - Metal analysis - Plants (botany) - Regression
analysis - Trace elements
Uncontrolled terms: Kelp - Regression models
Classification Code: 461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 481.2 Geochemistry - 801.2
Biochemistry - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Treatment: Theoretical (THR)
Database: Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.