Article Review: Freshwater Resources and Oceanic Pollution

Part One: Summary of Article

Researchers from Maine and Connecticut set out to determine if lead was a common pollutant in the oceans around the globe. When the amount of a substance - such as lead, in the case of this study - in a given sample is more than the amount of the same substance in the Earth's crust, this is called the enrichment factor. Researchers wanted to study the amount of lead in the earth's oceans as it was absorbed by living organisms. Therefore, the researchers needed a test subject that would be exposed only to lead found in the ocean and not to land-based lead. They also needed a test subject that would be able to traverse all of the global oceans.

The ocean is the ecosystem the researchers were evaluating in this study and therefore they needed an animal that would be confined to this ecosystem. While seals and sea lions are frequently used in research studies and are easy to track, the researchers had to forego this option for an animal that was strictly ocean-bound. Also, the researchers could not use a sedentary specimen such as a coral reef because the goal of the study was to evaluate the oceans of the entire world. Similarly, a particular type of fish would not do because fish often live in particular areas of the ocean off coasts.

With all these factors to consider, the researchers decided to study the enrichment factor in the sample of skin biopsies of sperm whales. The sperm whale was chosen because it is a strictly oceanic animal, meaning that the only environment to which it is exposed is the ocean. Also, the sperm whale, “has a global distribution” – meaning that the sperm whale travels the oceans of the globe – “and a high trophic level” – meaning that the sperm whale is high on the food chain (Savery et al., 2014).

Researchers collected 337 skin biopsies over the course of more than five years. The samples were collected from 17 different regions around the globe. Of the 337 samples, lead was detected in 315 of them. The global average amount of lead was 1.6 ug/g (monogram of lead per gram of sample). The smallest amount of lead detected was 0.1 ug/g and the largest amount was 129.6 ug/g. The highest amounts of lead were found in oceanic regions of Papua New Guinea, the Bahamas, and Australia. With these results, the researchers determined that lead “is widely distributed with hotspots in some regions” (Savery et al., 2014).

Part Two: Critical Evaluation

According to the material presented to us in the class, the data collected by the researchers is entirely plausible. The amounts of lead found in the skin biopsies of the sperm whales are realistic, while also still being scientifically compelling and significant. Also, from what we have learned, the selection of the sperm whale as a test subject seems to be a logical and reliable choice.

There are a couple of points that seem odd about this research study, however. For one, there was not a great deal of statistical analysis or cell analysis that went on in this study. Simply put, the researchers were testing for quantities of a substance in a sample and then compared the quantities amongst the samples. If the researchers collected the data from 2000 to 2005, it is puzzling that they waited nine years before publishing the article.

What could account for this delay is the need for such an article. In recent years, marine biologists have been gathering quite a dedicated following in the public eye. Since there have been numerous cases of whales washing up on the Pacific coast and new or very rare species being discovered, as well, perhaps the timing of the article's publishing is strategic. By waiting for a time when more people are interested in marine biology, water pollution and health hazards to marine animals, the researchers could be hoping to get additional funding or, at the very least, public support.

Another point to mention is that the researchers state that, "This is the first global toxicological dataset for Pb [lead] in a marine animal" (Savery et al., 2014). With that being said, we cannot make any claims about this study's reliability. Without other studies to compare it to, the study is not reliable. Only with replication and supporting data can a study be considered especially meaningful and useful in interpreting real-world information. It will take several additional studies over the next several years for the data presented in this study is found to be reliable. However, if it is the aim of these researchers to be pioneers in this field of data collection, they may hope to be selected for a grant to continue their research and provide their own additional research studies to give the first reliability. If that is the case, we must question the integrity of the researchers. Preferably, multiple research studies of the same caliber and focus would be conducted by different parties with different interests and priorities. Then we would have a sample of studies to compare against one another without concern of one group’s interests overwhelming the validity and reliability of a study.

It is also interesting that three of the researchers have the same last name. While this may seem inconsequential at first, it does call for an added evaluation of the researchers’ motives. If it is a family that is building a life around research funding, we must ask ourselves as information consumers to what lengths would these individuals go to ensure the success of their family and their research as a supportive family base.  

Reference

Savery, L. C., Wise, S. S., Falank, C., Wise, J., Gianios, C., Thompson, W. D., Perkins, C., Zheng, T., Zhu, C., and Wise, J. P. (2014). Global assessment of oceanic lead pollution using sperm whales (Physeter macrocephalus) as an indicator species. Marine Pollution Bulletin, 79, 236-244.