A few days ago, between May 19th and June 5th, San Diego hosted the 66a meeting of the International Whaling Commission (IWC) Scientific Committee (SC). During 2 weeks, delegates from 33 countries plus invited participants from different countries and organizations were discussing several issues related to conservation and management of cetacean populations. A total of 13 Sub-committees considered more than 100 research and working papers during parallel sessions, starting very early in the morning and lasting some days until late evening. During the last 3 days there were plenary sessions where reports of each Sub-committee were adopted. The annual Report of this meeting is available online and I’ll summarize here some of the most relevant issues discussed at the meeting.
Despite being the meeting of the Scientific Committee, these annual meetings are so far from being strictly scientific since the SC provides advice to the IWC Commission that meets every 2 years to make decisions regarding management and conservation of cetacean populations. Many political interests are involved here since, as it is expected, the IWC is polarized between pro-whaling nations and conservationist nations.
One of the most controversial topics that were expected for this year was the discussion of the new proposal of Japan (known as NEWREP-A) to resume whaling in Antarctica, despite a landmark ruling by the UN’s International Court of Justice last year ordering Japan to stop hunting in the Southern Ocean. An expert panel comprised of 6 current members of the Committee and 4 external scientists met in Tokyo at the beginning of the year, and revised this proposal and concluded that there wasn´t enough information to complete a full review of the program and that the current proposal did not demonstrate the need for lethal sampling to achieve objectives that could be reached with existing data and ongoing non-lethal methods. The Panel submitted a report with many recommendations on this proposal 40 days before the meeting, so during the SC meeting proponents had the chance to answer to the Panel. During the meeting a letter from a group of almost 500 scientists from 30 countries opposing the proposal was presented. Finally, after long discussion, the Committee agrees that the analyses recommended by the Panel should be completed, and that progress should be reviewed again next year.
Moving to an opposite side of the meeting, many threats faced by cetaceans were addressed and recommendations were made regarding entanglements, ship strikes, marine debris, climate change, oil spills, and chemical pollution, among others.
Whale entanglement is a growing problem around the oceans and since 2012 training workshops has being conducted under the auspice of the IWC to build a global network of professionally trained and equipped entanglement responders. Until now 336 individuals from 19 countries have been trained. During this meeting the possibility to establish an IWC global entanglement database hosted by the IWC was considered.
Ship strike is an important issue considered by the SC since many species of whales and dolphins are vulnerable to collisions with vessels. There were several discussions around overlap of ship routes and cetacean distributions, and the effectiveness of some ship strike mitigation measures, such as avoid areas with known concentrations of whales, or reduce speed while transiting those areas. One of the world’s busiest shipping routes is the southern coast of Sri Lanka which also has high densities of blue whales. A study presented at this meeting indicates that a 15nm southward shift in ship routes would reduce collision risk by 95%. Another case of study considered was the eastern Mediterranean where ship strikes are a significant threat to the “Endangered” population of sperm whales. In both cases, the Committee recommended to work with the relevant authorities of each country and the shipping industry to provide advice on alternative routing options. A paper presented information on abundance estimate for sperm whales in Canary Islands which indicated that the reported human-induced mortality rate may not be sustainable in the area. The Committee recommended further studies to identify critical habitat and evaluate the overlap in distribution patterns of shipping with sperm whales.
The Committee expressed concern about the continued persistence of polychlorinated biphenyls (PCB) – chemical compounds with high environmental toxicity- especially in the Northern Hemisphere, despite the overall decline in their use and manufacture. It recommended that research efforts continue to better understand this persistence in the environment, determine PCB sources and identify mechanisms to reduce further PCB input into the marine environment.
Another form of pollution in the ocean is anthropogenic noise which can have severe impacts on cetaceans since most of them rely on sounds to sense their environment and communicate with conspecifics. During this meeting, unfortunately, there was very little discussion on anthropogenic ocean noise and its adverse impacts on cetaceans. One of the most widespread sources of ocean noise is commercial shipping. High levels of noise could mask (prevent hearing) relevant sounds for cetaceans. The Committee recommended a focal-topic session on masking sound with emphasis on noise from commercial shipping for the next year’s meeting and also encouraged submission of papers on the effectiveness of marine mammal observers on board vessels.
The increasing amount of debris (plastic, wood, glass, metal, lost fishing gear, etc.) in the world’s oceans has become a major cause for concern. The IWC is working to mitigate potential threats. At this meeting an update on recent published research into marine debris and the impacts on cetaceans were presented. According to this review the cumulative quantity of plastics available to enter the ocean from land is predicted to increase by an order of magnitude by 2025. The Committee agreed that it’s necessary to improve our understanding of the extent and significance of marine debris impacts on cetaceans.
Moving to the Southern hemisphere, several documents were presented and discussed in the framework of the Southern Ocean Research Partnership (SORP) whose main focus is the development of non-lethal cetacean research in the Southern Ocean, with the aim of getting a full understanding of the post-exploitation status, health, dynamics and environmental linkages of the populations of cetaceans. Since 2014, Argentina is leading one of the SORP project and two field trips were made to the Western Antarctic Peninsula and South Orkneys Island/ Islas Orcadas del Sur to conduct passive acoustic monitoring and visual surveys on cetaceans. Members from WDC’s Latin America are part of the research staff and they have presented results from their last voyage in January-February 2015 at this meeting. Humpback whales were the most frequently seen species in the Western Antarctic Peninsula, particularly in the Gerlache Strait, followed by Fin whales around the South Shetland Islands. Acoustic and/or visual detections of orcas, hourglass, dusky, Peale’s and Commerson’s dolphins, sperm, beaked, minke, sei whales were registered. Another paper was presented documented cetacean presence with a passive acoustic recorder deployed near Elephant Island, Antarctica from March to July 2014. Fin whale acoustic activity was extensive and persisted at very high levels, preventing detection of blue whale signals if present throughout the recording period. Three different beaked whale signals were classifiable, two of them corresponding to the sounds recently described by researchers from WDC’s Latin America in collaboration with the Scripps Institution of Oceanography. Sperm whales, killer whales, and as yet unidentified dolphins were detected, but their occurrence still needs to be quantified. These are the first broadband, long-term acoustic findings collected near Elephant Island that encompass most cetacean species expected to occur in these waters. The acoustic record is on-going and will lead to a better understanding of seasonal relative abundance and habitat use of the shelf break area by cetaceans.
Last year, the assessments of Southern Hemisphere (SH) humpback whale breeding stocks was completed and during this meeting a synthesis of the results was presented. The assessments suggested that the number of humpback whales in the SH before commercial whaling was around 140,000. Currently seven humpback whale breeding stocks are recognized in the SH for which different patterns of population recovery were estimated. However during the meeting it was highlighted that these model projections should be improved using trend information that is currently available, since they are based on estimates of abundance that are, in some cases, more than ten years old.
The Committee reiterates its serious concerns for the Arabian humpback whale population given the evidences of small abundance and genetic isolation, along with a high mortality and a rapid development of anthropogenic activities in the area, including whale watching (WW). During further discussions it was noted that there is a potential for expansion of WW industries to areas within the Arabian Sea and efforts to manage WW regionally in the Arabian Sea must be made.
A clear example that unregulated WW can cause severe impacts on cetaceans is the case of Bocas del Toro, Panama. Several studies showed that dolphins changed their behavior in presence of tour boats. This is a small population and several dead animals were found with injuries caused by boat propellers. A paper presented during this meeting showed that almost 3/4 of boat operators was noncompliant with boat distance requirements, with respect to maneuvering and with the requirement for limited number of boats. However, tourists support regulations for boat operators and better environmental protection in the region, and boat operators agree that protecting the local dolphins is important. Thus the Committee agreed that the situation in Bocas del Toro must be addressed through three steps: authorities engagement; education of boat operators and tourists; and support research.
The Small Cetaceans (SM) sessions started with a review of the taxonomy and population structure of bottlenose dolphins (Tursiops spp.) in the Indo-western Pacific region. Many genetic studies of bottlenose dolphins around the world have reported genetic differentiation among populations. The purpose of this review was to clarify understanding of the genus taxonomy across the region. Studies showed that T. aduncus and T. truncatus are clearly and consistently distinguishable across many different areas. However, given that data related to the taxonic status of T. australis is discordant and further work is needed to discuss the application of different markers and analytical tools used for species/subspecies/unit to be conserved delineation in Tursiops. Next year, taxonomy and population structure of bottlenose dolphins in North Atlantic (including the Mediterranean, Black and Caribbean seas and the Gulf of Mexico) and South Atlantic will be reviewed.
Unfortunately, new information on the status of the vaquita (an endemic porpoise of the Gulf of California, Mexico) is disturbing! A 67% decline in vaquita acoustic activity from 2011 to 2014 was found. For many years, the main threat to this species has been entanglement in gillnets used to catch shrimp and the endangered totoaba fish. The SC acknowledged the recent actions taken by the Government of Mexico to address the conservation of vaquitas through a two-year gillnet ban and increased enforcement. However, to save this species from extinction there is an urgent need of collaborative efforts of many groups including both governmental and non-governmental parties. It was highlighted that during this two-year emergency closure period fishermen should be trained and equipped to use alternative fishing gears that do not threaten vaquitas. The Committee also requested that the IWC Secretary send letters to the CITES Secretariat and to Chinese authorities expressing its strong concern about the impact of the illegal totoaba trade on the vaquita.
The situation of the critically endangered Maui’s dolphins is not better. The most recent abundance estimate is 55 individuals with a decline rate of 2.8–3.2% per year. Current protection measures are applied only in approximately 19% of their assumed total range and a continued population decline is expected. Three issues were raised during the discussion: the need to assess the offshore distribution of Maui dolphins, the need to increase trawler observer coverage in order to better assess bycatch rates, and whether passive acoustic monitoring devices could be deployed to assess Maui dolphin habitat use. An updated abundance estimate is projected for next year using a new genetic mark-recapture method. It was stressed that given the many uncertainties surrounding this small population, precautionary measures should be taken. The SC reiterated its previous recommendation that inmediate management actions should be taken to eliminate bycatch of the species throughout their known range, together with an ample buffer zone.
A two year study of passive acoustic monitoring of the harbour porpoise population in the Baltic Sea estimated population size at 447 animals reaffirming that this population is critically endangered. Given that bycatch is considered the most serious threat to this population the SC recommended that the Baltic countries should maintain efforts to monitor abundance and bycatch levels.
An acoustic detector «Pontoporia Acoustic Detector» developed by researchers of Fundación Cethus in collaboration with WDC Latin America, the Western Hemisphere Migratory Species Initiative (WHMSI) and the Organization of American States (OAS) was presented. This tool can detect and distinguish vocalizations of both calves and adults of franciscana, and is available for other research teams working on this species. The SC welcomed this initiative which may be useful to study population structure and abundance on this endangered species. During the meeting researchers working on the species, including researchers from WDC, proposed franciscana as a possible candidate for a Small Cetacean Task Team (SCTT) and the SC agreed. The SCTT consists of an intersessional team of experts that will assist the SC in providing timely and effective advice to prevent extinction of endangered populations of cetaceans. In October 2015, a meeting of the Consortium of Franciscana will be held in Brazil, where discussion of the creation of a Conservation Management Plan (CMP) for this species will begin and the resulting report will be presented at next year’s meeting.
Actually, there is a CMP for Southern Right whales to try to increase the understanding of the factors causing the high mortality of the species around Península Valdés. Studies showed that the population size is still increasing but the growth rate has declined and if elevated rates of calf mortality continue for another decade or two, the population’s growth is expected to slow substantially. Long-term monitoring and research on this population was recommended as well as to implement actions to address the gull harassment problem.