Ethical Debate: Killing sharks for science?

While attending last year’s American Elasmobranch Society conference, I was asked to fill out a survey concerning my views on lethal shark research. My response, along with those of many other participants, has now been analyzed and written up into a new essay in the Journal of Conservation Biology. Michelle Heupel and Colin Simpendorfer argue that lethal sampling of some individual sharks is sometimes necessary in order to get the data needed to protect those animals’ entire species. However, attitudes about conservation in general and sharks specifically are changing, and many (including these authors) feel that this is starting to affect marine biology as a science.



The authors note that:

“One noticeable result of the increase in concern about sharks is that more students enquiring about graduate school who are interested in working on sharks are indicating they are not willing to participate in projects that may harm sharks. This occurs before they know which species are involved, the status of that species, or what benefits could be gained from lethal sampling. This suggests their perspective is not rooted in science, but is ethical, political, or emotive.”

Scott from Thriving Oceans likes this changing attitude, and points out that it

“definitely goes beyond sharks and speaks to greater societal attitudes. There’s a problem and our oceans need fixing.  And I am hoping that this change in attitude is not limited to those aspiring to be ichthyologists and marine biologists, but highlights growing awareness amongst consumers.”

It is undeniably true that certain important information can only be gained through lethal sampling. One of the main examples of this is “age and growth” data. Managers need to know how big certain species get, how quickly they grow, and how big they are when they are reproductively active. This kind of data is absolutely critical for any species management plan, and the best way we can get it is by looking at the vertebrae of sharks (like tree rings, shark vertebrae develop annual markings which can be clearly viewed under a microscope). You can’t look at shark vertebrae while they are still attached to the shark, and you can’t remove vertebrae without killing the shark.

Vertebrae from a gummy shark, image from Officer et al. 1996.

Sometimes sharks need to be killed to generate data that will help manage entire species or entire ecosystems.  Other times, lethal research techniques are used to answer less vital questions, or they are used when non-lethal techniques would do. I once witnessed a parasitologist kill a healthy shark that we had caught in order to harvest gut parasites from it when sharks that had died less than twenty minutes ago as a result of being caught were available.  The shark he killed was an Atlantic sharpnose, which are incredibly abundant in this region, but killing it was completely unnecessary.

This is an issue that tugs right at my heartstrings.  I got into this line of work because I care about sharks and I’m concerned about what’s happening to them. The thought of killing sharks troubles me because I am aware of their ecological importance and the reality that many species face extinction.

Although I have participated in lethal “age and growth” studies for other scientists, my own research involves non-lethal sampling. I have no objection to lethal sampling if it addresses vital concerns and there are no alternative acceptable methods, but I’m more interested in performing research that does not involve the further destruction of sharks. Killing a shark for research elicits strong emotions for me and I’d prefer to leave those methods to other scientists.

Heupel and Simpendorfer close their essay with this passage:

“The reality remains that a large amount of basic information is needed for conservation and management of shark species to be successful. The gathering of basic information should not be ignored, and lethal sampling to gather this crucial information should not be condemned. Where possible or necessary, nonlethal approaches should be used, but agenda-driven and emotive approaches should not be a substitute for decision making on the basis of scientific information.”

Do you think that killing a few individual sharks in order to create good management plans to protect entire species is ethically justified?

Does my desire to avoid killing sharks limit me as a scientist? Does this growing trend among graduate students negatively affect shark science as a field?

Does it make any sense for me to not want to kill Atlantic sharpnose sharks, which are not endangered, because they physically resemble (and are related to) endangered species of sharks?

HEUPEL, M., & SIMPFENDORFER, C. (2010). Science or Slaughter: Need for Lethal Sampling of Sharks Conservation Biology DOI: 10.1111/j.1523-1739.2010.01491.x

June 1, 2010 • 12:06 pm