There’s no place like home
Think about the places that shape your daily life – your bedroom, your kitchen, your workplace, maybe your favorite local pub or regular commuter route. Some of these places probably feel essential to your comfort, routine, and wellbeing. Well, fish aren’t so different. They depend on specific environments for shelter, food, spawning, feeding, and growing to maturity – areas known as Essential Fish Habitats (EFHs).
In short, EFHs are the places fish need to survive and thrive. These habitats come in all forms, from seagrass beds to vibrant coral reefs, and support fish in specific stages of their lifecycle. Some provide a safe haven from predators (think baby fish hiding out in mangrove forests), while others present ideal environmental conditions for growth (like skates laying their eggs in the crevices of rocky boulder reefs).
Salmon spawning grounds are another great example of an EFH, freshwater habitats where salmon gather, pair off, and listen to Barry White before spawning the next generation. After hatching, young salmon remain in these areas (cosy and protected) until they’re big enough to take on the big blue sea. Famously, salmon have been shown to return to the very same stretches of river when its their time to reproduce, often crossing thousands of miles to do so.
Now, imagine what happens when those vital habitats start to disappear.
Trouble in paradise
EFHs represent a delicate balance between species and their environment, which means they are susceptible to a wide range of human activities, such as fishing, dredging, mining and transport – to name a few. Nursery habitats can be destroyed with the pass of a scallop dredge, or migratory channels (highways for fish) can be disrupted by shipping noise and collisions. Larger threats like climate change and ocean acidification also impact these habitats [2].
Sometimes the damage done to EFHs is irreversible, especially for those habitats that take many years to naturally form and mature. For example, horse mussel reefs provide shelter for diverse marine life, including juvenile whiting (Merlangius merlangus), cod (Gadus morhua) and queen scallops (Aequipecten opercularis). These reefs are formed from the accumulation of living and dead shells over many decades and some reefs are estimated to be hundreds of years old! Once destroyed, the reefs are extremely difficult to reestablish – which has led to their permanent disappearance from many regions.
Turning the tide
Just like hospitals, train stations, and the middle isle of Lidl – EFHs are fundamental to (marine) life as we know it. The protection of these habitats is key to sustainable fisheries management and in the long run, global food security. Many of these sensitive habitats also deliver wider ecosystem services (or benefits) to human society. For example, in addition to their roles as nursery areas for juvenile fish, biogenic reefs, seagrass and saltmarshes also store huge amounts of carbon (also termed blue carbon) – a key talking point as we move through the continued warming of our climate.
The conservation angle here is self-evident; we are in the midst of a biodiversity crisis, and EFHs are some of the most ecologically important habitats in the marine environment. The protection of these habitats can support the recovery of Threatened species, maintain vital ecosystem functioning, and directly support ecosystem-based management approaches.
Across Europe and the UK, we’ve seen some great moves in terms of EFH designations in recent years, including:
- Strait of Sicily FSRA: Europe’s first Essential Fish Habitat (EFH) zone fully aligned with the Common Fisheries Policy (CFP), pioneering the closure of trawling in critical nursery habitats to safeguard young marine life (link).
- The first highly protected marine protected areas (HPMAs) designated in UK waters (Allonby Bay, NE Farnes Deep, Dolphin Head), with explicit nursery/spawning ground safeguards (link).
- The first ever flapper skate EFH, an egg-case nursery, was discovered and protected in Scottish waters (link).
Researching EFHs (responsibly)
As global attention shifts toward EFHs, there is a growing need for data to support their identification and eventual protection. Traditional fisheries surveys can give a rough sense of where EFHs might be, but they fall short when it comes to pinpointing them. Sure, a spike in juvenile skate might hint at a regional hotspots, but how many were correctly identified? And what about the lesser-known, non-target species these surveys aren’t even looking for? Many species simply slip through the cracks. Even more worrying, these methods often rely on extractive or destructive techniques, which is inappropriate when dealing with fragile, threatened habitats and species. Instead of relying on opportunistic data, we must be proactive. It’s time we shift to targeted, non-invasive monitoring, designed for EFH identification.
At Fjordstrong, we specialise in cutting-edge, non-destructive video solutions that deliver critical biodiversity data without compromising the ecosystems we study. Using our fleet of towed cameras and ROVs, we can scan seabeds for nursery habitats (like egg-case nurseries), while our 3D stereo-imaging technology allows us to measure a fish and determine its maturity – all without touching a single scale on it’s head. In practice, these data can inform life history research, EFH designation, environmental impact assessments (EIAs) and much more!
We have applied our solutions to several EFH projects, including:
- Surveying potential egg-laying sites for the critically endangered Flapper Skate around the Orkney islands (Scotland) and the Maidens (Northern Ireland) -> Link here
- Identifying nursery habitat potential for offshore renewable energy scour protection -> Link here
- Providing survey solutions and data consultancy to support HPMA monitoring across the UK -> Link here
For more information on how we can support your projects, get in touch today!
Cover photo: © Shane Gross
[1] https://www.fisheries.noaa.gov/topic/laws-policies/magnuson-stevens-act
[2] Limpinsel, D.E., Eagleton, M.P. and Hanson, J.L., 2017. Impacts to essential fish habitat from non-fishing activities in Alaska: EFH 5 year review: 2010 through 2015. Available at: https://repository.library.noaa.gov/view/noaa/17256
