Study identifies nine research priorities to better understand NZ’s vast marine area



New Zealand’s coastline spans a distance greater than from the south pole to the north pole.
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Rebecca Jarvis, Auckland University of Technology and Tim Young, Auckland University of Technology

The islands of New Zealand are only the visible part of a much larger submerged continent, known as Te Riu a Māui or Zealandia. Most of New Zealand’s sovereign territory, around 96%, is under water – and this means that the health of the ocean is of paramount importance.

Most of the Zealandia continent is under water.
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New Zealand’s marine and coastal environments have significant ecological, economic, cultural and social value, but they face many threats. Disjointed legislation and considerable knowledge gaps limit our ability to effectively manage marine resources.

With the UN decade of ocean science starting in 2021, it is essential that we meet the challenges ahead. To do so, we have asked the New Zealand marine science community to collectively identify the areas of research we should focus on.

Ten important science questions were identified within nine research areas. The full list of 90 questions can be found in the paper and policy brief, but these are the nine priority areas:




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1. Food from the ocean

Fisheries and aquaculture are vital sources of food, income and livelihoods, and it is crucial that we ensure these industries are sustainable. Our study has identified the need for new methods to minimise bycatch, mitigate environmental impacts and better understand the influence of commercial interests in fishers’ ability to adequately conserve and manage marine environments.

2. Biosecurity

The number of marine pests has increased by 10% since 2009, and questions remain around how we can best protect our natural and cultural marine heritage. Future directions include the development of new techniques to improve the early detection of invasive species, and new tools to identify where they came from, and when they arrived in New Zealand waters.

3. Climate change

Climate change already has wide ranging impacts on our coasts and oceans. We need research to better understand how climate change will affect different marine species, how food webs might respond to future change, and how ocean currents around New Zealand might be affected.

Climate change already affects marine species and food webs.
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4. Marine reserves and protected areas

Marine protected areas are widely recognised as important tools for marine conservation and fisheries management. But less than 1% of New Zealand’s waters is protected to date. Future directions include research to identify where and how we should be implementing more protected areas, whether different models (including protection of customary fisheries and temporary fishing closures) could be as effective, and how we might integrate New Zealand’s marine protection into a wider Pacific network.




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5. Ecosystems and biodiversity

While we know about 15,000 marine species, there may be as many as 65,000 in New Zealand. On average, seven new species are identified every two weeks, and there is much we do not know about our oceans. We need research to understand how we can best identify the current baseline of biodiversity across New Zealand’s different marine habitats, predict marine tipping points and restore degraded ocean floor habitats.

6. Policy and decision making

New Zealand’s policy landscape is complicated, at times contradictory, and we need an approach to marine management that better connects science, decision making and action. We also need to understand how to navigate power in decision making across diverse interests to advance an integrated ocean policy.

7. Marine guardianship

Marine guardianship, or kaitiakitanga, means individual and collective stewardship to protect the environment, while safeguarding marine resources for future generations. Our research found that citizen science can help maximise observations of change and connect New Zealanders with their marine heritage. It can also improve our understanding of how we can achieve a partnership between Western and indigenous science, mātauranga Māori.

8. Coastal and ocean processes

New Zealand’s coasts span a distance greater than from the south pole to the north pole. Erosion and deposition of land-based sediments into our seas has many impacts and affects ocean productivity, habitat structure, nutrient cycling and the composition of the seabed.

Future research should focus on how increased sedimentation affects the behaviour and survival of species at offshore sites and on better methods to measure physical, chemical and biological processes with higher accuracy to understand how long-term changes in the ocean might influence New Zealand’s marine ecosystems.

9. Other anthropogenic factors

Our study identified a range of other human threats that need more focused investigation, including agriculture, forestry mining and urban development.
We need more research into the relative effects of different land-use types on coastal water quality to establishing the combined effects of multiple contaminants (pesticides, pharmaceuticals, etc) on marine organisms and ecosystems. Pollution with microplastics and other marine debris is another major issue.

We hope this horizon scan will drive the development of new research areas, complement ongoing science initiatives, encourage collaboration and guide interdisciplinary teams. The questions the New Zealand marine science community identified as most important will help us fill existing knowledge gaps and make greater contributions to marine science, conservation, sustainable use, policy and management.The Conversation

Rebecca Jarvis, Research Fellow, Auckland University of Technology and Tim Young, Marine Scientist, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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In the remote Cambodian jungles, we made sure rare Siamese crocodiles would have enough food



The Siamese Crocodile once lived in Southeast Asian freshwater rivers, but now fewer than 1000 individuals exist.
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Paul McInerney, La Trobe University

For nine hours, my colleague Michael Shackleton and I held onto our scooters for dear life while being slapped in the face by spiked jungle plants in the mountains of Cambodia. We only disembarked either to help push a scooter up a slippery jungle path or to stop it from sliding down one.

With our gear loaded up on nine scooters – 200 metres of fishing nets, two inflatable kayaks, food for five days, hammocks, preservation gear for collection of DNA, and other assorted scientific instruments – we at last arrived at one of the few remaining sites known to harbour the critically endangered Siamese crocodiles.




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The Siamese crocodile once lived in Southeast Asian freshwater rivers from Indonesia to Myanmar. But now, fewer than 1000 breeding individuals remain.

In fact, during the 1990s the species was thought to be completely extinct in the wild. Then, in 2000, scientists from Fauna and Flora International found a tiny population in the remote Cardamom Mountains region of Cambodia.

We travelled to this remote wilderness in 2017 to determine habitat suitability for the reintroduction of captive-bred juvenile Siamese crocodiles. We wanted to understand the food web there to see whether it contains enough fish to sustain the young crocs.

Our journey would not have been possible without the help of Community Crocodile Wardens – local community members who patrol the jungle sanctuaries for threats and record crocodile presence. Wardens also conduct crocodile surveys further afield to discover new populations or to identify new areas of potential suitable crocodile habitat for juvenile releases.

Our recent study found to ensure the species survives, reintroduction locations must be protected from fishing pressure – both from a food supply perspective, but also from risk of entanglement in nets.

A species in decline

When we arrived at our site, northwest of the village of Thmor Bang, our day was capped by what we came to know as the standard evening downpour, despite assurances that we had, in fact, timed our trip for the dry season.

Kayaks were inflated, nets set, and sampling was underway. This proved laborious – to ensure crocodiles didn’t drown, we couldn’t leave nets unattended in the water overnight, but instead checked them every hour until morning.

Siamese crocodiles are generally not aggressive to humans, but they come into conflict with people when caught in fishing nets.

This often leads to the crocodile drowning and the fishing net being ruined. It’s a disaster on both counts, because fish is the only source of protein for many local communities in Cambodia.

Like many other apex predators around the world, the Siamese crocodile is also in decline because of habitat destruction and poaching for their skins.

Their potential large size and generally placid nature means they are highly prized by crocodile farmers who use the skins for handbags and footwear. Crocodile farmers also often hybridise the Siamese crocodiles with other non-native crocodile species.




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This means programs for Siamese crocodile reintroduction and breeding must carefully genetically screen all young crocodiles bred in captivity to make sure they’re not actually hybrids, so the “genetically pure” wild populations can remain.

Finding fish bones in croc poo

Despite a pretty good understanding of captive Siamese crocodile behaviour and biology, very little is known about Siamese crocodiles in the wild, such as what they eat or how much food they need to raise an egg to adulthood.

Our only reliable indication of diet comes from scats (crocodile poo or “shit of croc” as we came to call it) collected along the river banks inhabited by remnant populations.

Carefully collected poo samples containing scales and bones tell us fish and snakes make up a significant proportion of the Siamese crocodile diet.

But the shrouded, mystical, extremely remote and virtually inaccessible jungle in the Cardamom Mountains has ensured we know next to nothing about fish communities within habitats set for the release of captive crocodile. And this information is particularly important for prioritising release locations for captive bred juveniles.




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We spent four days sampling fish communities and then repeated the process at two other equally remote locations within the Cardamoms, requiring two days travel between each.

We saw groups of gibbons moving through the forest and macaques climbing down from trees to drink at the river. But at last we spotted a wild Siamese crocodile after dark, swimming in our morning bathing pool, on our second-last day.

Ultimately, we distinguished 13 species of fish from the Cardamom Mountains, confirming the presence of two previously unconfirmed species groups for the region.

What’s more, we found fish density was highest in areas with more Siamese crocodiles, and lowest in areas with more human fishing pressure.




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Understanding the food web of crocodile reintroduction sites is important, because conservation managers need to understand the ecological carrying capacity of the system – the number of individual crocodiles that can be supported in a given habitat. Learning this is especially important when historical information does not exist.

Preservation of fish stocks within Siamese crocodile habitats is critical for survival of the species. But a key challenge for natural resource managers of the Cardamom Mountains is balancing crocodile density with local fishing necessity, and to do this, we need more information on Siamese crocodile biology.The Conversation

Paul McInerney, Research Fellow, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.