IUCN World Conservation Congress motions relevant to cetacean conservation

The IUCN World Conservation Congress will be held in Marseille in June 2020. Motions to be tabled at the congress will be available for online consultation by IUCN members (for what this means, see https://www.iucn.org/about/union/members) from December 11th 2019 and March 11th 2020.  After that, they will be available to the membership for electronic vote from April 29th to May 13th.

Below we provide a compilation of all the motions that are directly and indirectly related to cetaceans.  Click on the title of each motion to find out more details.  The full list of motions is available via the WCC website here.

WCC Motion number Motions Directly mentioning cetaceans/marine mammals
027 Reducing impacts of incidental capture on threatened marine species
110 Safeguarding the Endangered narrow-ridged finless porpoise (Neophocaena asiaeorientalis) off the Korean Peninsula
118 Renforcer la protection des mammifères marins par la coopération régionale
Motions relevant to protection of marine mammal habitat
009 Protecting rivers as corridors in a changing climate
014 Aquatic biodiversity conservation of shallow marine and freshwater systems
015 Supporting the Lower Mekong Basin countries with the transboundary management of water resources, ecosystems and biodiversity
017 Cooperation on transboundary fresh waters to ensure ecosystem conservation, climate resilience and sustainable development
024 Restoring a peaceful and quiet ocean
026 Establishment of a mid-frequency active (MFA) sonar moratorium for naval exercises conducted in Macaronesia
031 Seascapes working for biodiversity conservation
033 For the urgent global management of marine and coastal sand resources
035 Enhancing the resilience of coastal areas in the face of climate change
037 Ocean impacts of climate change
066 Guidance to identify industrial fishing incompatible with protected areas
093 Conservation, restoration and sustainable management of mangrove ecosystems
094 Linking in situ and ex situ efforts to save threatened species
097 Reducing marine turtle bycatch: the important role of regulatory mechanisms in the global roll-out of Turtle Excluder Devices
101 Setting area-based conservation targets based on evidence of what nature and people need to thrive

 

CMS Scientific Council Meeting and Outcomes Relevant to Cetacean Conservation

By Gianna Minton (24 Nov 2019)

 

Background and summary

 

The Convention on Migratory Species (CMS) Scientific Council met from 12-14 November 2019 in Bonn, Germany. Its task was to evaluate ongoing activities and draft resolutions, decisions and proposals and make recommendations to member governments that will meet in the triennial Conference of Parties (COP) in Gandhinagar, India from 15-22 February 2020.

A range of issues relevant to cetacean conservation are addressed by the Council. IUCN CSG Deputy Chair Giuseppe Notarbartolo di Sciara is the CMS Councillor for Aquatic Mammals (including cetaceans). The following issues that were discussed in the aquatic working group of the Council and will be taken forward to the COP next February. CSG members may want to track some of these issues and communicate with the relevant CMS focal points if they are keen to support proposed measures:

 

Threats/issues affecting cetaceans

 

 

Proposals for Concerted Actions (regional government-backed collaboration for a species or population)

 

 

Progress on existing Concerted Actions:

 

A number of progress reports were endorsed with an addendum that included clarification of procedures for extension or continuation into the next triennium (between COP 13 in 2020 and the next COP in 2023):

Ganges River dolphins strongly alter their acoustic behaviour in response to underwater noise, finds study from India

Article written by Nachiket Kelkar1,2
 1Ashoka Trust for Research in Ecology and the Environment, Bangalore, India.
2 Member, IUCN Cetacean Specialist Group.
Email: nachiket.kelkar@atree.org

 

The impacts of underwater noise on marine cetaceans are starting to be relatively well understood across the world’s oceans. Noise can trigger responses ranging from avoidance to chronic stress, to permanent hearing loss and sometimes even stranding, injury, and mortality (see here for a recent review of impacts: Erbe et al. 2019; https://doi.org/10.3389/fmars.2019.00606). Direct investigations of the effects of noise on freshwater cetaceans, however, remain very limited.

 

Ganges River dolphins Platanista gangetica gangetica are listed as Endangered on the IUCN Red List, and are found only in the shallow, turbid rivers of the Indian subcontinent (India, Bangladesh and Nepal). They are almost blind and continuously emit high-frequency echolocation clicks to sense their environment, navigate, and locate prey (fish and shrimp). Importantly, Ganges River dolphins do not produce whistles, and their acoustic repertoire is restricted to modulations of their clicks. A belief even among some experts has been that the mostly low-frequency underwater noise from vessel engines does not affect these river dolphins. However, riverine environments have different background conditions that can complicate assessments of noise impacts on dolphins. Reverberation and reflection effects in shallow river habitats are complex. Further, space is naturally restricted for river dolphins, limiting their ability to avoid vessel traffic and noise as both vessels and river dolphins need adequate depth.

 

A study published in Scientific Reports https://www.nature.com/articles/s41598-019-51664-1 by Mayukh Dey, Jagdish Krishnaswamy, Tadamichi Morisaka, and Nachiket Kelkar shows that underwater noise, especially that produced by propeller-induced cavitation, can alter the acoustic behaviour of dolphins in the Ganga River in India. At a point in March when vessel traffic peaked and recorded flows in the river were at their lowest, the dolphins actually suppressed their echolocation activity (click rate) and  also showed shifts in the peak frequency and sound pressure level of their clicks, indicating fairly significant impacts of ambient noise on echolocation. The noise also masked their communication clicks, and caused increases in metabolic stress.

 

The study also found that at shallow river depths, the impacts of underwater noise were even more severe. It thus highlighted the importance of considering underwater noise pollution as a factor that should be considered in the management of ecological flows in the Ganga mainstem and in tributaries where waterways for ship navigation are planned.

 

The study attains particular importance in today’s conservation context. Many large rivers in the Ganga-Brahmaputra basin, where river dolphins occur, are to be transformed into major waterways by the Government of India. In 2016, a letter jointly signed by the IUCN Director-General and the Chair of the Species Survival Commission, expressed concern about the potential impacts of waterways development on river ecology and dolphin conservation: https://iucn-csg.org/iucn-letter-to-the-indian-minister-of-environment-concern-over-the-impact-of-indias-national-waterways-act-on-ganges-river-dolphins/. Between 2016 and 2019, the issue has been discussed often in environmental policy debates in India. Indian waterways authorities are also in the process of conducting studies on the impacts of dredging and noise on the dolphins. It is expected that the findings of this recent study by Dey et al. will inform the species recovery programs and conservation initiatives being carried out for the species at national and state levels and by civil society (NGOs).

 

Spectrogram showing the echolocation clicks of a Ganges river dolphin (top), and another spectrogram of clicks (bottom) when a motorised vessel passes. The clicks that are seen to be masked, are masked by cavitation noise. The high-frequency range of such noise clearly interferes with the acoustic signalling of Ganges river dolphins. Graphs: courtesy of Dey et al. (2019).

Citation: Dey, M., Krishnaswamy, J., Morisaka, T., & Kelkar, N. Interacting effects of vessel noise and shallow river depth elevate metabolic stress in Ganges river dolphins. Scientific Reports 9, 15426 (2019).

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