Sound. It travels faster and further through
water than air and in an environment where light does not penetrate very deep, its is one of the most important senses for marine animals including whales,
dolphins and porpoises. Cetaceans as they are also known use sound for
communicating, finding food and navigating their way around the ocean. The
great baleen whales such as those our little Morgan encountered in the Azores, use low
frequency sound to communicate over thousands of kilometres, toothed whales and
dolphins like Orca use sound to echolocate in order to find their food and
their way. Clicks and whistles are also used to communicate, and for some
species distinguish between individuals in other words they have names!
Scientists have even shown that different populations of Orca for example have
specific vocalisations and even that different groups within the same
population have different dialects.
The amazing properties of sound in water have made
it very useful to humans as well. Using sound we can identify objects at huge
distances, we can work out what type of rock exists below the seabed, and we
can find valuable deposits of oil and gas used to fuel our modern day lives.
The issue is that as humans we are increasing
the amount of sound in the ocean, and this is having some terrible impacts on
whales and dolphins. Strandings, where whales and dolphins beach themselves and
injuries have been linked with active sonar. Hearing sensitivity can be
affected, either temporarily or permanently. Calls can be masked so that
individuals cannot hear them or they have to change the way they make their own
calls in order to be heard – a bit like us raising our voices in a very noisy
room. Sound can affect behaviour too, causing disturbance or avoidance of
areas. The level of impact depends on the intensity and frequency of the sound,
and also on the individual.
For the exploration of oil and gas, around
the worldwide a number of countries have introduced legislation and guidance in
order to try and reduce the impact of this sound on whales and dolphins. While
arguments may continue about whether oil and gas exploration should continue,
especially in certain sensitive areas, ultimately as long as people are going
to search for such deposits something needs to be done to protect whales and
dolphins as much as possible. Methods include delaying the start of a sound if
whales or dolphins are close by, increasing the level of noise gradually over a
period of time in order to warn animals in close vicinity, shutting down noise
sources when animals come within a certain distance. All of which involve
having experienced marine mammal observers, to spot whales and dolphins and to
advise people about guidelines. And inevitably training is needed.
Morgan at the Pro-MMO lectures |
This week our little Morgan joined
participants on a Marine Mammal Observer (MMO) course run by Gardline Environmental Ltd., learning the guidelines set out for UK waters by the Joint
Nature Conservation Committee (JNCC).
With a day of lecturers in a class room, our
little Morgan learnt all about the properties of sound, the reasons human made
sounds for oil and gas exploration can be so bad for whales and dolphins, and
what these guidelines advise in order to reduce the impacts. Next it was off on
a ferry in order to put into practice what they had learnt and to get some
experience spotting and identifying whales and dolphins. What better place than
the Bay of Biscay. With regular ferry’s crossing a range of habitat from
shallow shelf waters, steep slopes, stretches of deep water and underwater
canyons. The area covers habitat perfect for a range of dolphins and whales,
and is one of the best places in Europe to see some of the most elusive whales,
the beaked whales.
Out on deck scanning for marine mammals |
With the weather a mixed bag and sea conditions ranging from choppy to completely flat calm, our little Morgan and the other candidates spent time on the ferry’s deck taking part in role plays and putting into practice the mitigation methods learnt in the class room. With wave after wave of common dolphin they even got to practice delaying operations! As the ferry crossed over the underwater canyons in the southern part of the Bay, a treat for Morgan and the other participants were two of those elusive beaked whales, this time Cuvier’s Beaked Whale, surfacing right next to the ferry!
Arriving in sunny Santander there was time to
reflect on a wonderful days whale watching and to discuss all that they had
practiced, before getting back onto the ferry for the return leg…. And of
course the MMO exam!
In sunny Santander with the Pro-MMO candidates |
With expert guidance and tuition all 10
candidates, and our little Morgan passed to become JNCC trained MMOs, ready to
head off on survey vessels around the UK and beyond, in order to protect whales
and dolphins from this particular form of underwater sound.
Find out more about the JNCC guidelines for seismic surveys, piling (installing rigs and wind turbines) and explosives, and find out more about Marine Mammal Observers here.
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