Marlborough Express - Weekend Express
The problem with kina
Your routine fishing trips may be causing more harm to the environment than you realise, warns Marlborough Girls’ College student Kiede Surgenor.
OPINION: During the past school year a group of environmental science students and I have been mentored by Dr Nick Shears to develop a better understanding of kina barrens — including the causes and solutions.
Most know that kina is an invasive species, but do you know what enables kina to invade and overpopulate?
It may come as a surprise that recreational fishing actually has a huge effect on the overpopulation of kina in our sounds. This overpopulation is causing deeper issues that demand to be acknowledged.
To understand this issue we must first understand kina. Some of the most important aspects being, what kina eat and what eats kina. Blue cod, snapper and crayfish are all main predators to kina and coincidentally, the amount of these species in the Marlborough Sounds is slowly decreasing.
A consequence of this decrease is a rapid increase in kina populations, as there are less and less predators to balance the amount of kina.
So what does more kina mean? Why is this bad? To circle back, a key aspect in this topic is what kina eat, which is kelp. Less predators to kina in our oceans means more kina and more kina means less kelp.
So why is less kelp bad? The importance of kelp in our oceans begins at kelp being a foundational species, kelp provides crucial food and habitats for a myriad of other marine organisms, which is part of the reason why kelp forests are one of the most productive ecosystems in the world.
Kelp forests are also a huge positive contributor to the carbon cycle by absorbing carbon dioxide through photosynthesis. Not to mention that kelp keeps our oceans clean. From storm debris to pollution, we have kelp to thank for restoring the balance.
The continued rapid decline in kelp forests would cause detrimental effects that expand beyond imaginable outcomes... pollution and climate change effects would become undeniably noticeable and species would go extinct.
By this stage, recreational fishing would be strictly forbidden in a desperate attempt to save our waters so weekend fishing trips would be a thing of the past and jumping into the sparkly blue ocean on a hot summer's
day would also become only a fantasy. If the foundation collapses, the rest of the structure falls too, think “jenga”. This is why it is so important that this issue is acknowledged now, before the effects are irreversible.
Of course recreational fishing is only part of the problem but it is a big part of the problem. So, what are the possible solutions? There is no simple solution but some solution methods include; more marine protected areas, increasing the kina catch limit, kina removal and harsher fishing restrictions.
There has been an abundance of research done on each of these solutions. Based on research conducted by Dr Nick Shears at Auckland university, and the data collected over the past school year, it is found that removing the kina doesn't solve the issue. Removing kina is only a temporary solution to an ongoing problem: when kina is removed, they will eventually come back.
Going to the root of the issue, which is recreational fishing, is a much more effective way to resolve the issue. By implementing more restrictions on fishing and more protected areas, the number of snapper, crayfish and blue cod improve which restores the balance in these ecosystems. Protected areas will eventually begin kelp restoration but to speed up the process, lab grown kelp spores being added to the protected areas implements a “two pronged strategy”.
In conclusion, the best solution to minimise the increasing amount of kina barrens in our sounds is more marine protected areas as well as a kelp restoration project to speed up the process.