Marine Mammals... Cute, Cuddly, And In Crisis

by Sheril R. Kirshenbaum     Department: Health & Life Sciences

Marine mammals captivate people around the world.  Look to Hollywood and every genre from kids flick to science fiction can't seem to get enough of these charismatic critters.  Just ask coca-cola...

But what is it about whales, dolphins, polar bears, and seals that captures our collective imagination? It's hard to fathom the complex lives of these animals that seem so majestic, yet completely mysterious hidden beneath the ocean surface and the adoration of marine mammals is near universal. Wander into the Hall of Ocean Life at the American Museum of Natural History and surely every child will be gazing up in wonder at the life size blue whale. Most adults will too for that matter. There's something mystical about a world within our own--different from all we know yet exploding with with biodiversity stranger than anything we might imagine.

And yet despite a collective appreciation of marine mammals, we continue go about harming them in a myriad of ways from destructive fishing practices to industrial pollutants and beyond.  In fact, twenty-five marine mammal populations in the US of A are currently classified as either endangered or threatened under the Endangered Species Act (ESA) and thirty are listed as depleted under the Marine Mammal Protection Act (MMPA).  While these policies aim to reduce the greatest threats, we've got a long way to go.

To get readers up to speed, I've outlined five of the most serious here, but keep in mind, there are plenty more...

I. Noise Pollution
Shipping, oil and gas exploration, drilling, and Navy sonar have increased the level of noise pollution in oceans. The impacts on marine mammals have not yet been fully studied, but likely have serious repercussions on orientation, hearing, and communication for these animals.  We do know noise from military sonar and underwater seismic testing has been linked to the deaths of whales and dolphins.

II. Ship Strikes
There are lots of ships out traversing the great big blue and sometimes they collide with marine mammals.  In Maine I would constantly learn of strikes with Atlantic northern right whales and many small, vulnerable, populations of other species.  While there are restrictions on vessel traffic based on time of year (i.e. coinciding with reproductive season, migration routes, etc), there's a heck of a lot we don't understand about the way strikes are impacting populations.  Additionally, many species already endangered such as manatees are often victims of collisions with recreational vehicles as well.

III. Commercial Whaling
Japan, Norway, and Iceland are keen to end the International Whaling Commission (IWC) moratorium on commercial whaling.  After phasing out commercial whaling, Japan resumed 'scientific whaling', to study stock structure and products of this research program are sold to Japanese consumers.  As I've said before, just because you use the term 'science', doesn't make it scientific...

IV. Fishing Activities
Commercial fishing results in the deaths of many harbor porpoise, sea lions, dolphins, and whales.  Entanglements with fishing gear also account for half of the deaths of the North Atlantic right whales.  There is not a reliable way to determine how many marine mammals are killed or injured by discarded gear and problems are compounded because of trophic cascades due to predator prey relationships.

IV. Chemical Pollutants
Increased chemical pollutants from specific sources, industry, agricultural runoff, and power plants are also a problem. Orcas, whales, and polar bears suffer from high levels of toxins accumulating in their bodies which hinders their recovery.

Our favorite film stars certainly have a lot to deal with these days... and remember--all of these threats are not acting independently.  So folks, since many of us love these critters, we ought to do a better job of protecting them.  And if we aim to do something beyond lip service, it will take more than appealing to the animal lovers among us.  We must begin framing the problem in ways that resonate beyond those already convinced.

Tags: marine mammals, polar bears, whales