SCUBA April 2024 issue 144 | Page 51

Kerry MacKay sets out the actions we can take to ensure our dive boats don ’ t become unwitting spreaders of invasive species

Bigging-up biosecurity

Kerry MacKay sets out the actions we can take to ensure our dive boats don ’ t become unwitting spreaders of invasive species

Here are the key steps we should all do to stop the spread :

Do you know your responsibilities as a recreational water user ? Are the biosecurity police going to confiscate your dive kit or boat ? With many of us enjoying exciting dive trips , now is a great time to brush up on our responsibilities as divers .

Biosecurity is about taking action to minimise the introduction , spread and establishment of invasive non-native species ( INNS ). Sometimes also known as aliens .
Let ’ s break that down a bit more . ‘ Invasive ’ species are those that take over a habitat . They usually cause damage to the environment , economy , and human health .
‘ Non-native ’ or ‘ alien ’ species are organisms that have been introduced to a place they would not naturally be found . Introductions are usually through human activities . This can be accidental or intentional .
For example , the most commonly farmed oyster in the UK is the Pacific oyster . This is a permitted and intentional introduction of an alien species when being used for aquaculture . However , they are invasive outside the oyster farm setting , outcompeting our native oyster populations .
Uncleaned props can carry invasive species
Zebra mussels , however , were accidental introductions . This , like most marine INNS , was introduced through ballast water from large ships .
A favourite fact of mine is that around half the oxygen we breathe comes from the sea , so it ’ s in our own best interests to look after it . INNS can have devastating environmental impacts , spread disease , restrict navigation , block waterways , clog up propellers , and cost billions to manage .
Currently , efforts to stop the spread of INNS are reliant on water users taking responsibility for the role we play as potential spreaders . There is , however , the threat of legislation to be brought in to make biosecurity mandatory . While good for cracking down on the spread of INNS , this would be a hindrance to many water users .
■ Check – Inspect your equipment , boat , and trailer for any bits that may be clinging on . Remove anything you find and bin it . Don ’ t throw it back in the water or leave it on land thinking it ’ ll die . Many can grow back from just a tiny fragment .
■ Clean - Remember that some invasive species can be / have microscopic life stages and are invisible to the naked eye . Give everything a good rinse with fresh water , as you should anyway . Don ’ t forget to flush out the engine , rinse ropes , and anchor chains , and get those hard-toreach places on your trailer .
■ Dry – Ensuring surfaces have time to dry out properly is a vital part of the process . Often it is the drying that does the killing . There may still be microscopic bits in places that you ’ ve not quite managed to flush or scrub , but drying them to a crisp will finish the job .
■ Report sightings – Ideally , take a photo of it in situ . You will also need to record the date , what species you think it is , and the location . The easiest way to submit your record is through the iRecord app or website . If you ’ re not confident about species ID , speak to your local Seasearch group .
Common places to find invasive marine alien species are man-made surfaces . Boat hulls , ropes , buoys , and pontoons , are all places we divers are uniquely suited to investigate .
The GB Non-Native Species Secretariat Information Portal ( www . nonnativespecies . org ) has lots of useful information including species ID sheets . It is also worth checking out The Green Blue ( www . thegreenblue . org . uk ). They offer free resources , including their Coastal Biosecurity Signage Kit that you can display to encourage everyone to do their part to stop the spread .
I certainly would hate to inadvertently bring a marine alien home with me from a fun dive trip , or infect a wonderful site I ’ ve travelled to visit . Let ’ s all do our part to protect the waters we love . �
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