Home Editorial CMEPS Halifax Biennial Conference on the Biology of Marine Mammals

CMEPS Halifax Biennial Conference on the Biology of Marine Mammals

203
0
Humpback whale breaches in natural spectical

by Roy Mulder

This report summarizing some of the highlights of the Halifax conference. It is written from the perspective of a conservationist attending a science conference. The conference was well attended by around 2,000 marine mammal scientists from around the world. This report covers some general information and is written from a Canadian interest and perspective.

Photographing orcas in the wild

The large Canadian concern at the conference was the population of North Atlantic right whales in eastern Canada. As of late there have been 16 whales found dead generally in the region bounded by the Magdalen Islands, PEI and the New Brunswick coastline. One of the main concerns is that although this population numbers are around 500 animals, there are only 100 that are females of calf bearing years, and their mean longevity is only 14 years, while their potential lifespan is 60-80 years. From studies, it is clear that just about every one of them has encountered fishing tackle in their lifetimes. Although entanglement is often blamed as a key factor in their demise, necropsies of dead whales is indicating that ship strikes may well be the main contributor to these deaths, while in US waters entanglement is the primary cause.

One of the organizations displaying at the conference was the Campobello Whale Rescue Team. This impressive group formed of fishermen interested in addressing entanglements lost one of their members in a rescue this year. The group documents entanglements and proactively works on releasing whales entangled by trap lines. They clearly know their risks and work hard to improve their methodology to make it safer for both the whales and the rescuers.  The Sea Mammal Education Learning and Training Society was also displaying in the poster session. Their contribution to entanglements is a system that uses traps without lines and an inflatable trap return system.  This system uses a GPS locator and RF transmitter to keep a record of trap locations for pick up after being laid.  Hopefully the future will see some solutions to both entanglements and ship strikes. Rope-less fishing gear while in development remains a major hope for the future. It is noteworthy that at the current rate of loss N Atlantic Right whales will be extinct in 23 years.

A large segment of the conference was focused on acoustics and satellite tagging.  These talks ranged from the acoustic response to the use of shipboard echo sounders, to controlled exposure experiments with full-scale military mid-frequency sonars in four cetacean species. Clearly whales are being affected by acoustic disturbance and mitigating these disturbances will be required if we are to avoid disrupting the cetaceans. In some cases, this could easily be resolved by organizing shipping routes and in other cases, more care must be exercised by military when conducting their activities.  One of the talks indicated that there may be a direct linkage between tagged female whales and a resultant negative affect on pregnancy. Considering the number of tagging going on, this may be a factor that needs to be addressed. Some senior marine mammal scientists voiced concerns that the morbidity attached to the tagging of N Atlantic right whale has a demonstrated increase on calving interval, the calving rate for tagged animals being half or less that of untagged animals.

Aquatic mammals used as bait, especially in the global shark trade is a concern in global fisheries. Creating the demise of one species to facilitate the demise of another is a questionable practice. Studies indicate that marine mammals play an essential role as an ocean variable. Although many of the sessions covered various scientific aspects of marine mammals, conspicuously absent were studies of marine mammal prey and the beneficial role of pinnipeds.  There was a good talk on integrating science into marine conservation management: a knowledge exchange framework that enhances the delivery of science into management action. Conservationists will need to learn to work more closely with scientists to validate concerns about management of specific populations. Some flawed tidal turbine studies (n=1) seemed to indicate that acoustically tagged pinnipeds (grey seal) avoid the turbines, although there was no information presented regarding the effect of turbines on prey species. There is a general lack of well designed, arm’s length studies of the impact of tidal turbines on marine wildlife in the UK, and this technology is now being deployed on Canada’s east coast in the Minas Basin. Again, without adequate study. Currently there is also a study to see if an acoustic deterrent device can be used to mitigate seal-fisheries interactions. The battle between seal advocates and fishermen is an ongoing problem.

There is a considerable effort being put into finding ways to reduce entanglements with fishing gear. Studies are being done on the tensile strength of ropes used in fishing operations, with studies demonstrating a 1700 pound breaking strength being a critical value to assure juvenile whales can escape gear in the N Atlantic right whale population.  There are some hopes that the right strength of rope to conduct fishing activities, may be enough to fish, but not enough to keep cetaceans entangled, however the gold rush fishery for snow crab requires gear that greatly exceeds this critical breaking strength requirement.

One of the areas of advancement in studies is the new automated dorsal fin matching. Automated systems for fluke identification have advanced making for a more accurate, easier identification and is reducing human ID time. New algorithms are now advancing studies and are providing better methodology than those used in the past.

An overarching theme at the conference was the number of species at risk. There are significant concerns about Hectors dolphin and Vaquita porpoises. The onset of the attempt to save the last 30 Vaquitas in the Gulf of California was ongoing at the time of the conference with US and Mexican government participation and was reported on. Since that time, it is apparent that this species, which is highly stress prone, has not done well in the interim captivity holding facilities, despite efforts of the foremost marine mammal scientists and conservationists, with the loss of one animal and forcing release of a second. We will likely see the demise of many species of dolphins in the near future. One of the largest populations that will be affected is all of the river dolphin populations in the 8 great river systems around the world, with the Baiji already having become extinct in China in recent history. Between population expansion and pervasive pollutants in rivers, we will be forced to watch as all river dolphins go into irreversible decline. It was a very moving experience to hear a scientist who devoted his life to the science of cetaceans describe what he expects to be the demise not of just a species, but of an entire clade, the river dolphins, due to human effects exclusively.

Drones seem to have quickly been adapted, to be used for scientific studies. They are being used to study everything from social interactions to actually going low enough to gather samples from whale blows. As much as this is advancing knowledge it does bear asking the question how much negative affect drones have.  Drone studies are advancing the ability to determine cetacean health by documenting body shapes, which indicate well fed (or not) cetaceans. Of particular interest was a sail drone which seemed to be a relatively non-invasive way of gathering information. Some poster presentations indicated cetaceans showed awareness of drones in their vicinity during studies so although their use may help to improve some of the human pursuit related effects seen in marine mammal research, their use is not wholly benign.

There was little discussion on the negative effects of drones, and their use seems to be regulated differently in many parts of the world. This may be a good place for conservationists to establish some best practices, like we are seeing with whale watching companies. Again, the divide between science and conservation still remains an obstacle in doing what is best for the animals.

Summary:

Many of the luminaries in marine mammal research, from Hal Whitehead to Sam Ridgeway to Michael Moore, attended and presented at this meeting, which attracted about 2000 people from around the world. The big-picture, take home messages were:

The vast majority of the public think the whales were saved by Greenpeace 30 years ago, while species are continuing to go extinct.

The single most used term at this meeting was “Anthropocene”. It is clear that the overwhelming majority of negative effects on all marine mammal populations are human derived.

The Vaquita, with 30 animals remaining, is already regarded as being extinct by many marine mammal biologists, and initial attempts to capture and conserve the last few animals are failing, despite a massive and well-funded effort due to the inherent nature of the species and its lack of ability to adapt to captivity.

The Vaquita was forced to extinction because it was bycatch in an illegal fishery for the swim bladders of a species of fish used in traditional Chinese medicine, and the Mexican authorities failed, due to corruption, to stop the illegal harvest, in addition to this, shark fin harvest is causing the killing of marine mammals for bait.

Conclusions:

Approaches to consumers of TCM and shark fin need to be explored to dry up the market for products that are causing the extinction of species.

The North Atlantic right whale will become extinct unless government forces the development of rope-less gear, enforces speed limits in areas the animals traverse and develops a real-time system for monitoring the movements of the animals and a dynamic system for rapidly closing areas to shipping and diverting ship traffic.

The reason Northern Right whales are now moving to new areas versus their historical feeding grounds are not understood by science, but it is likely that shifting food sources are causing these animals to move into areas where their cultural knowledge of food availability and hazards is poor and this is causing an increase in ship strike in the northern range.

Blaming global warming for changes in plankton distribution will not save this species, a much more dynamic and fast acting system that could cause changes in navigation directions to mariners and fishermen needed to prevent ship strike and gear entanglement on a day by day real time basis, needs to be developed and implemented rapidly.

Tidal turbine studies need to be undertaken by arm’s length researchers, not the industry, before more widespread deployment occurs in Canadian waters. The UK turbine industry is poised to move into maritime waters in Atlantic Canada and there is a complete lack of quality research on the potential biological impacts of this, other than engineering type studies on the turbines.  The single experience of the tidal turbine in Annapolis Royal NS in the 1980s, with the subsequent complete loss of the local Annapolis River fishery, is a case in point which most people are unaware of.

Roy Mulder
President
Canadian Marine Environment Protection Society