Ewan Garvey, one of Project Seagrass’ Interns for the 2025-26 academic year, explores how seagrass can provide protection for coastal communities. As the seasons transition from autumn into winter, storms often become a pressing concern for coastal communities. In recent years, the growing impacts of climate change have become increasingly
Jasper Brown, one of Project Seagrass’ Interns for the 2025-26 academic year and 3rd Year Student in BSc Zoology with Marine Zoology at Bangor University, explores the need for both active and passive restoration to secure a future for our important seagrass habitats. Marine ecosystems worldwide are under threat. Rising
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Sea snails are a hugely diverse group of marine gastropod found in all over the world. There is such a vast range of different colours, sizes, diets and
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. The small spotted catshark (Scyliorhinus canicula) is a small shark species growing up to 1 meter long and can be seen around European and North African coastlines. They
In an article for Halloween, Grace Cutler, one of Project Seagrass’ Interns for the 2025-26 academic year, explores the frightening reality of continued seagrass loss as a result of anthropogenic activity and how this in turn threatens seagrass’ role in supporting people and planet. Werewolves are struck down by silver
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. The snakelocks anemone is a funny looking creature commonly found around the UK. They have up to 200 long, wavy tentacles and can grow on average to about
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. The Brent Goose Branta bernicla is of a similar size to a Mallard duck, making it one of the smallest goose species in the world. They are a
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Sea hares are odd looking creatures. They are mostly soft bodied but have a small internal shell, which separates them from their close relatives – sea slugs. The
Ewan Garvey, one of Project Seagrass’ Interns for the 2025-26 academic year, explores how seagrass can provide protection for coastal communities. As the seasons transition from autumn into winter, storms often become a pressing concern for coastal communities. In recent years, the growing impacts of climate change have become increasingly clear: extreme weather events once considered “once-in-a-decade” now seem to strike far more frequently. In response, governments and communities are looking for protective solutions, investing heavily in sea defence systems, ranging from sandbags to seawalls. But what if nature has already developed a solution? Enter seagrass. Seagrass’s unique characteristics make it a powerful ally in protecting coastlines. Unlike concrete walls or other flood defence systems, seagrass meadows work with natural processes to reduce erosion and flooding, while also creating vital habitat for marine life. How Seagrass Protects Our Shores Root FixationMuch like how trees stabilise the soil in forests, seagrass root systems anchor sand and mud in place, reducing sediments from being washed away during storms. This helps to maintain the structure of beaches, providing more stable coastal habitats. Dissipation of Wave EnergyWhen waves pass over seagrass meadows, the blades create friction. This slows the water, disperses energy, and reduces the force that reaches the shoreline. This means water travels up the beach less and can lessen flooding events. Challenges Hard-engineered coastal defences such as rock armour can cost upwards of £1 million for just a 35-metre section. Seagrass restoration is also expensive, and to date has been largely funded through philanthropic and government funding mechanisms. Seagrass restoration is not without challenges; newly planted seeds are vulnerable to being washed away or buried by shifting sediment before they can properly establish. Seagrass also requires good water quality; too much pollution can prevent seedlings from developing. In many areas, improving river and coastal water quality must go hand in hand with restoration for projects to succeed. A Blended Solution Is seagrass the silver bullet for coastal protection? Not entirely. By blending natural and engineered approaches, we can create more sustainable, resilient coastlines—ones that not only protect us from storms but also support thriving marine ecosystems. Combining engineered solutions such as breakwaters or seawalls with seagrass meadows could reduce wave energy and sediment loss, which would lower the stress on the artificial defences. This could result in cheaper, smaller sea defence structures, reducing both environmental impact and cost. References and Extra Research “Seagrass as a nature-based solution for coastal protection” by Forrester, Leonardi, Cooper & Kumar (2024) Infantes et al. (2022) — Seagrass roots strongly reduce cliff erosion rates in sandy sediments Donatelli et al. (2018) — “Seagrass Impact on Sediment Exchange Between Tidal Flats and Salt Marsh, and The Sediment Budget of Shallow Bays” Bricheno, L. M., et al. “Climate change impacts on storms and waves relevant to the UK and Ireland.” MCCIP Science Review 2025 (2025).
Jasper Brown, one of Project Seagrass’ Interns for the 2025-26 academic year and 3rd Year Student in BSc Zoology with Marine Zoology at Bangor University, explores the need for both active and passive restoration to secure a future for our important seagrass habitats. Marine ecosystems worldwide are under threat. Rising temperatures, ocean acidification, and water pollution are just a few of the key drivers in the decreasing quality of our marine ecosystems. Researchers have found that many aquatic species are shifting poleward at an average rate of 70 kilometres every decade (Melbourne-Thomas et al., 2021) – a vast response to changing conditions. Species such as the American Lobster, Cushion Star, and Humboldt Squid have nearly doubled their latitude range, showing the clear extent of this poleward shift in marine species (Pinsky et al., 2020). Why are they moving? One crucial reason is habitat loss. Seagrass meadows, coral reefs, and kelp forests are disappearing worldwide, reducing opportunities for biodiversity and removing essential nursery habitats for marine life. The solution is clear: we must conserve and restore. Across the globe, charities and organisations are embracing active restoration – direct interventions to rebuild habitats. The work consists of planting seagrass, reforesting mangroves, and coral Gardening. All of which provide crucial environmental benefits: large carbon sinks, coastal protection, and providing nursery habitats. Seagrass planting involves transplanting seeds and rhizomes near existing meadows (do Amaral Camara Lima et al., 2023). Coral gardening uses nurseries to grow coral fragments, which are later transplanted to reefs that support approximately 25% of all marine species (Rinkevich, 2014; Gallagher, 2025; Pacific Coastal and Marine Science Center, 2022). Mangrove reforestation involves planting seedlings along suitable coastlines (Zahra Farshid et al., 2022; Bimrah et al., 2022). These methods are being implemented worldwide, from the Persian Gulf in western Asia to the Firth of Forth in Scotland. Yet, challenges persist. Active restoration projects are costly, often relying on charitable donations and grants (Paling et al., 2009). Despite these hurdles, active restoration works, a recent review by Danovaro (2025), found an average success rate of 64% across 764 projects. Is active restoration enough? However, success depends on environmental conditions; water clarity, for example, is critical for seagrass survival due to photosynthesis requiring sufficient light. Declining clarity, driven by pollution, bottom trawling, and dredging, increases turbidity, which limits restoration efforts (Paling et al., 2009). This is where passive restoration comes in Passive strategies focus on removing environmental pressures and creating conditions for ecosystems to heal naturally. Examples include implementing policies to regulate fertilizer use and reduce nutrient runoff, as well as enforcing Marine Protected Areas (MPAs). These acts will reduce eutrophication in our waterways and lead to a more stable marine environment, leading to the eventual reduction in coral bleaching and seagrass meadow reduction. MPAs have been shown to restore ecosystem functions such as predation (Cheng et al., 2019), highlighting their critical role in maintaining biodiversity. Conclusion While MPAs are just one example, they perfectly highlight the value of passive restoration in its entirety. The greatest benefits come from integrating passive and active approaches. By enforcing regulations and establishing strict no-trawl zones, we can reduce nutrient loads and sedimentation. Through these efforts, our marine ecosystems will one day thrive again, meaning we get to see the animals and plants we so dearly care about. References Bimrah, K., Dasgupta, R., Hashimoto, S., Saizen, I., & Dhyani, S. (2022). Ecosystem Services of Mangroves: A Systematic Review and Synthesis of Contemporary Scientific Literature. Sustainability, 14(19), 12051. https://doi.org/10.3390/su141912051 Bulmer, R. H., Townsend, M., Drylie, T., & Lohrer, A. M. (2018). Elevated Turbidity and the Nutrient Removal Capacity of Seagrass. Frontiers in Marine Science, 5. https://doi.org/10.3389/fmars.2018.00462 Cheng, B. S., Altieri, A. H., Torchin, M. E., & Ruiz, G. M. (2019). Can marine reserves restore lost ecosystem functioning? A global synthesis. Ecology, 100(4), e02617. https://doi.org/10.1002/ecy.2617 Danovaro, R., Aronson, J., Bianchelli, S., Boström, C., Chen, W., Cimino, R., Corinaldesi, C., Cortina-Segarra, J., D’Ambrosio, P., Gambi, C., Garrabou, J., Giorgetti, A., Grehan, A., Hannachi, A., Mangialajo, L., Morato, T., Orfanidis, S., Papadopoulou, N., Ramirez-Llodra, E., & Smith, C. J. (2025). Assessing the success of marine ecosystem restoration using meta-analysis. Nature Communications, 16(1). https://doi.org/10.1038/s41467-025-57254-2 do Amaral Camara Lima, M., Bergamo, T. F., Ward, R. D., & Joyce, C. B. (2023). A Review of Seagrass Ecosystem services: Providing nature-based Solutions for a Changing World. Hydrobiologia, 850(12-13), 2655–2670. https://doi.org/10.1007/s10750-023-05244-0 Gallagher, M. (2025, August 24). What Ecosystem Services Do Coral Reefs Provide? – Green Packs. GreenPacks. https://greenpacks.org/what-ecosystem-services-do-coral-reefs-provide/ Melbourne-Thomas, J., Audzijonyte, A., Brasier, M. J., Cresswell, K. A., Fogarty, H. E., Haward, M., Hobday, A. J., Hunt, H. L., Ling, S. D., McCormack, P. C., Mustonen, T., Mustonen, K., Nye, J. A., Oellermann, M., Trebilco, R., van Putten, I., Villanueva, C., Watson, R. A., & Pecl, G. T. (2021). Poleward bound: adapting to climate-driven species redistribution. Reviews in Fish Biology and Fisheries. https://doi.org/10.1007/s11160-021-09641-3 Pacific Coastal and Marine Science Center. (2022, June 27). Role of Reefs in Coastal Protection | U.S. Geological Survey. Www.usgs.gov. https://www.usgs.gov/centers/pcmsc/science/role-reefs-coastal-protection Paling, Fonseca, M., Katwijk, M., & Keulen, van. (2009). Seagrass restoration. In Coastal wetlands: an integrated ecosystems approach. (pp. 687–713). Rinkevich, B. (2014). Rebuilding coral reefs: does active reef restoration lead to sustainable reefs? Current Opinion in Environmental Sustainability, 7, 28–36. https://doi.org/10.1016/j.cosust.2013.11.018 Zahra Farshid, Reshad Moradi Balef, Tuba Zendehboudi, Dehghan, N., Mohajer, F., Siavash Kalbi, Hashemi, A., Afshar, A., Tabandeh Heidari Bafghi, Hanieh Baneshi, & Amin Tamadon. (2022). Reforestation of grey mangroves (Avicennia marina) along the northern coasts of the Persian Gulf. Wetlands Ecology and Management, 31(1), 115–128. https://doi.org/10.1007/s11273-022-09904-1
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Sea snails are a hugely diverse group of marine gastropod found in all over the world. There is such a vast range of different colours, sizes, diets and life strategies within the sea snail community. These are fascinating little creatures that deserve a lot more attention than they receive! A big issue for sea snails inhabiting shallow coastal areas is desiccation – drying out when the tide goes out. Some species, like periwinkles, will group together in rock crevices and excrete a gluey mucus to hold them in place and retain moisture. A lot of species have an operculum. This structure is attached to their foot and acts as a trapdoor. When the snail retreats into its shell, the operculum will seal shut, preventing moisture from escaping and the snail from drying out. Snail mating behaviour is both odd and fascinating. There are so many variations in the sea snail world – from self-fertilising hermaphrodites to standard sexual reproduction. Some species are your standard dioecious set up – within the species there are male individuals and female individuals where gametes from each are needed for reproduction. For example, the common whelk Buccinum undatum has separate males and females. The females will release pheromones to attract males and fertilisation will happen internally, allowing the production of egg capsules. Each capsule contains between 600 and 2000 eggs. Despite being in the same egg capsule, the developing embryo may still have different fathers as the females can mate multiple times and store sperm until the environmental conditions are perfect. Other snail species will gather in groups and release their gametes straight into the water column for fertilisation to take place. Shannon Moran / Ocean Image Bank Hermaphroditism is where one individual produces both male and female gametes. Some species such as bubble snails and mud snails are simultaneous hermaphrodites – they can produce both sets of gametes at once, meaning they can self-fertilise. Protandrous sequential hermaphroditism is when the individual started out as male but changes sex to become a female at some point throughout their lives. Species in the genus Crepidula (slipper snails) express this behaviour. The change in sex is thought to be influenced by their social situation – number, sex and size of other individuals in the vicinity. Some species will carry around their offspring on their shells. Males of the whelk species Solenosteira macrospira will carry the offspring of up to 25 other males. When mating, the female will glue capsules containing hundreds of eggs onto the males shell. As the eggs hatch, some of the first to break free will eat their siblings that are still developing inside the egg. Other species will glue their eggs to solid structures in the environment and leave them to raise themselves. Eggs can hatch into larvae which will travel with currents to help dispersal and mix populations and then settle down to develop after a few weeks. In other species, tiny, fully formed versions of the adults will hatch. Why am I telling you about sea snails? Because they love seagrass! Uk species such as the mud snail Peringia ulvae, banded chink snail Lacuna vincta, the bubble snail Haminoea navicular and perhaps the most recognisable common periwinkle Littorina littorea and netted dog whelk (Tritia reticulata) are all known to use seagrass meadows in at least one stage of their life cycle. Some snails, such as the dog whelk, will lay their eggs on the leaves of seagrass, attaching them with a mucus to hold them firm and preventing coastal currents from dislodging the eggs. Some species will eat the algae growing on the seagrass leaves. They use sharp, tiny teeth like structures to scrape the algae off the leaves. This is very important for the health of seagrass as too much algal growth will smother the plant, preventing sufficient light for photosynthesis to reach the leaf. There is evidence showing the presence of snails on seagrass increases leaf length and nutrient content (Jiang et al., 2023). Other benefits of these little critters Sea snails play a huge role in ecosystems and coastal environments. Their role as an indicator species helps us understand environmental health and can be used to measure levels of pollution and habitat quality. In some cultures, they are harvested for their meat and shells, creating important income streams for coastal communities. Snails form a vital part of many species diets, including birds, crabs and fish. Some species are detritivores – they will eat dead and decaying organic matter on the sea floor. This is a very important role as it prevents nutrient build up which can lead to algae blooms and disease outbreaks. Sea snails are even being used in scientific research to advance technologies. All snails have tiny teeth-like structures on their radula (a tongue-like mouthpart), however in some species these are super strong. Patella vulgate, a species of limpet, have some of the strongest in the world – the strength of their teeth is comparable to some of the strongest commercial carbon fibres and can withstand the pressures that turn carbon into diamonds (Sea Snail’s Teeth: Are They the Strongest Biomaterials in the World?, 2019). These properties are being studied for use in improving and adapting technology used in building planes, boats and dentistry. Researchers are investigating compounds in the venom some sea snails produce for possible use in medicinal drugs for pain relief and diabetes (Sea snail poison promises new medicines, 2018). If you want to find out more about these strange little creatures, I’d recommend these articles to start: 5 Sensational Sea Snail Species Sea Snail References: Sea snail poison promises new medicines | Research and Innovation. (2018). Projects.research-And-Innovation.ec.europa.eu. https://projects.research-and-innovation.ec.europa.eu/en/projects/success-stories/all/sea-snail-poison-promises-new-medicines Eren , R. (2019). Sea Snail’s Teeth: Are They the Strongest Biomaterials in the World? [online] Fountain Magazine. Available at: https://fountainmagazine.com/all-issues/2019/issue-132-nov-dec-2019/sea-snail-s-teeth-are-they-the-strongest-biomaterials-in-the-world. Jiang, Z., He, J., Fang, Y., Lin, J., Liu, S., Wu, Y. and Huang, X.
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. The small spotted catshark (Scyliorhinus canicula) is a small shark species growing up to 1 meter long and can be seen around European and North African coastlines. They generally live in shallow coastal areas and rarely go deeper than 100 meters around the British Isles, but in areas such as the Mediterranean they have been spotted swimming down to 400 meters deep. They love sandy, muddy or rocky seafloors where they feed on crab, molluscs and fish which they detect with their strong sense of smell and electrical sensors located in its snout. Sharks have really interesting skin. Tiny teeth-like structures called dermal denticles cover their whole body, giving the shark a course, sandpapery texture. These provide the shark with an armour like protection from other predators, but also from parasites, algae and barnacles that might think a sharks body would make a good home. Each denticle has a blood flow and is covered in dentine – the same thing as human teeth – to make them extra solid structures and are discarded and replaced throughout the sharks lifetime. Denticles also reduce drag whilst swimming, allowing the creatures to swim at high speeds. This particular property has been of interest to companies, who have mimicked the structure of the denticles with synthetic materials for human use. One such example is Speedo, who created a material called “Fastskin” for swimsuits that was so good it was banned from competitions, including the Olympics! Small Spotted Catshark egg in Seagrass Spotted catsharks are oviparous – meaning they lay their young in eggs to develop outside of the body. The female will lay her eggs in pairs in sheltered, shallow coastal areas. To keep the eggs safe during development, the female will attach the egg case to a solid structure – usually seaweed or seagrass. Once ready to lay the eggs, long tendrils at each corner of the egg will appear first. These are attached to a seagrass shoot or seaweed by the female swimming in tight circles around it. Once these tendrils are attached, the female will circle faster, pulling the rest of the egg from the cloaca and making sure it is firmly attached to the chosen structure. The eggs will develop for 8-9 months, depending on the sea temperature and then hatch into small versions of the adults. It is common to see spotted catshark egg cases washed up on beaches around the UK. If you’ve come across a small, roughly 5 -7 cm long, thin case with curly tendrils at each corner, chances are it was a spotted catshark egg case! Usually these are empty, but sometimes they will have been dislodged and wash up with the embryo inside. If you find one of these – made sure to put it in a deep rock pool and anchor it down so it doesn’t float back onto the beach! What is a spotted catsharks relationship with seagrass? This catshark uses seagrass mainly as a nursery for its young. As mentioned before, the females will wrap the tendrils of the egg cases around a solid structure such as seagrass, ensuring it doesn’t get washed away in currents and keeping the developing embryo safe. Dense seagrass meadows make perfect nursery’s once the sharks hatch from their eggs too. The meadows provide shelter from predators as well as a wide variety of food for the baby spotted catsharks to practice hunting. Adult spotted catsharks may also be spotted around seagrass meadows as a lot of their prey likes to hide between the shoots, such as crabs and small fish. Why is this species important? Unlike some of the other species mentioned in this blog series, spotted catsharks have little commercial/ human use. Some communities eat them but on a large commercial scale, they have little value. However, within ecosystems it has a couple of important roles. It is a mid-level predator, meaning it eats a wide variety of smaller creatures as part of its regular diet, but also can be prey for other bigger species, like other sharks and seals. The role of a predator is vital in maintaining healthy populations. For example, the spotted catshark loves to munch on crab, which can be quite destructive animals when their population grows too large. By keeping crab numbers at a healthy level, catsharks help maintain functioning ecosystems and happy seagrass meadows. Also, scientists can use spotted catsharks as indicator species. If they are present, it means the habitat has a healthy number of different species as the sharks wouldn’t stick around an area that doesn’t have enough food to support them. Reference : https://www.ebsco.com/research-starters/science/small-spotted-catshark
In an article for Halloween, Grace Cutler, one of Project Seagrass’ Interns for the 2025-26 academic year, explores the frightening reality of continued seagrass loss as a result of anthropogenic activity and how this in turn threatens seagrass’ role in supporting people and planet. Werewolves are struck down by silver bullets, vampires are defeated with wooden stakes; the environment is protected by seagrass. While it may not be as dramatic, the narrative that aligns seagrass as the ultimate solution to combating the environmental crisis is popular. As someone studying this remarkable habitat, it’s easy to see why. The only marine flowering plant in the world, seagrass offers numerous ecological benefits, supporting both our planet and humanity. Despite this, we risk ignoring the crux of the issue by relying on these green solutions. We keep polluting. It is because we continue to pollute our environment, be it through greenhouse gases, plastic pollution, or general waste production, that the very things that help to prevent the environmental crisis, are dying. A Natural Water Filter? While seagrass may not clean water bodies, it increases particle deposition rates by slowing the speed of waves and allowing more time for particles to sink to the ocean floor. Particles can then become trapped in the seagrass meadow and are prevented from ending up elsewhere in waterways. This process has been shown to capture excess nutrients, waste products, and even pathogens. A study conducted in the greater Seattle Metropolitan Area showed that mussels placed in seagrass habitats had 65% less relative abundance of some pathogens when compared to mussels placed in habitats without seagrass. Yet, the most apparent threat to seagrass, identified by UK researchers, is water quality. Like most plant species, seagrass can function in polluted water quality up to a point or ‘threshold value’. Similar to how humans can eat a certain number of toffee apples until it becomes too much and we get a sugar crash. Once this threshold is exceeded, seagrass will decline and, in some severe instances, disappear from the environment entirely. One such instance can be seen in the Chinese province Hainan, where researchers found that a dissolved inorganic nitrogen concentration of 8μM or above will cause seagrass meadows to disappear. This is because an excess of nutrients in water bodies, like nitrogen, stimulates the production of algae which blooms on the surface of the water and prevents sunlight from reaching seagrass beds. Additionally, some nutrients like ammonium and sulphides can have direct negative effects on seagrass growth. Fortifying our Coastlines Imagine a castle that is under attack. If it is strong and maintained, the castle will be better at defending itself against intruders. However, the next time it is under attack, there are holes and weak points left in it from the previous battle. Over time, this castle falls into disrepair and becomes a ruin, leaving it unable to protect its inhabitants. Seagrass is similar. Its inhabitants are our coastlines. Coastlines today are facing threats on all fronts. Sea level rise, extreme storms, and erosion are just some of the problems they experience. With that said, some have considered using seagrass as a way of minimising the impact of storms causing erosion in these areas. Through their matted root systems, called rhizomes, seagrass meadows have been shown to improve the stability of sediments and reduce wave energy before it reaches the shore in some hydrodynamic systems. Yet, seagrass is also harmed by these storms. Meadows that are struck by intense physical disturbances can be uprooted or die back, initiating a positive feedback loop where meadows in decline are more vulnerable to disturbances. This means when the next storm hits, seagrass not only will be more susceptible to decline, but they are also less able to protect our coasts. What About Carbon? Carbon storage is a phrase often thrown around. It may be the key reason why people are interested in seagrass as an answer to climate change. With anxiety surrounding our warming planet on the rise, this isn’t unprecedented. However, seagrass may not be quite the antidote we think it is. Recent evidence has shown that following disturbances, carbon stored in the soil of meadows may be re-released into their environment as carbon dioxide. Such disturbances can range from direct physical effects, such as dredging and construction work, or indirect global threats stimulated by climate change. A 2011 marine heat wave struck the West-coast of Australia, causing the reported loss of over 1000 km2 of seagrass in Shark Bay. Another instance of mass seagrass loss occurred in the Gulf of Mexico, where two seagrass species (Halodule wrightii and Syringodium filiform) disappeared following sea level rise in 2014. Without seagrass, the carbon stored in these soils is easily remineralised and released back into the environment. What’s Next? Thankfully, the main factor contributing to seagrass decline appears to be anthropogenic impacts such as dredging, overfishing, and agricultural runoff. This means that with changes in how we do things, we can stop the death of seagrass. However, this means seagrass mustn’t be painted as a plaster to patch up the pollution of the planet. To help seagrass, we must reduce pollution, reduce nutrient runoff, protect seagrass so it can protect us! References Ranking the risk of CO2 emissions from seagrass soil carbon stocks under global change threats Extreme climate events lower resilience of foundation seagrass at edge of biogeographical range Too hot to handle: Unprecedented seagrass death driven by marine heatwave in a World Heritage Area Rapid sea level rise causes loss of seagrass meadows Seagrass ecosystems as green urban infrastructure to mediate human pathogens in seafood Toxic effects of increased sediment nutrient and organic matter loading on the seagrass Zostera noltii Losses and recovery of organic carbon from a seagrass ecosystem following disturbance Continual migration of patches within a Massachusetts seagrass meadow limits carbon accretion and storage Mediterranean seagrasses provide essential coastal protection under climate change
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. The snakelocks anemone is a funny looking creature commonly found around the UK. They have up to 200 long, wavy tentacles and can grow on average to about 8cm wide. These anemones are common in rock pools as they like to attach themselves to a solid surface in sunny spots, however they are also commonly found attached to seagrass leaves. Their diet generally consists of plankton, tiny crustaceans, and small fish. To catch live prey, they use sticky stinging cells in their tentacles called nematocysts which emit a paralysing, sometimes lethal, venom on contact. This venom is mostly harmless to humans, generally only causing a small rash on contact. Snakelocks anemones in the Isle of Wight Snakelocks anemone tentacles are usually a deep green with purple tips. A symbiotic algae called zooxanthellae located in the tissue helps the anemone to survive by producing essential nutrients like glucose via photosynthesis. In return, the algae receive a safe stable environment to live. Due to this need for photosynthesis, the anemone needs light so generally won’t live more than 12 meters deep. Unlike other anemone species, the snakelocks rarely retracts its tentacles, allowing them to make the most of any sunlight. A recent study discovered that snakelocks anemones move their tentacles throughout the day to follow the sun whilst its body remains in one place, similar to sunflowers! This is commonly seen in plants, but never before in animals. It is thought this movement is caused by the algae living within their tentacles. You can read more about this here. The snakelocks anemone is a Cnidarian – a group of aquatic invertebrates also including jellyfish and corals. Cnidarians have a fascinating life cycle but to put it simply, they generally have 2 body forms – a swimming medusae and a sessile polyp stage and can reproduce either sexually or asexually. However, the snakelocks anemone completely lacks the free-swimming medusa stage. This means once the sperm and eggs are fertilised, which happens externally in the water column, the larvae drop down to create another polyp from which tentacles will grow. A more common method of reproduction is longitudinal fission. This asexual method involves the anemone splitting in half to create 2 identical individuals. This process can take between a couple of minutes to a few hours. So what is a snakelocks anemone’s relationship with seagrass? These anemones are commonly found in seagrass meadows around the UK. They attach and live on the leaves, providing the anemone with a stable, sunny habitat. The seagrass protects the anemones from drying up at low tide, meaning the anemone can be in shallower waters and get more sunlight without the risk of desiccation. Are snakelock anemones an important species? Of course! Every species has an important ecological niche, i.e. a role it plays within its environment that helps maintain a healthy functioning ecosystem. Some small creatures like to live within the tentacles of the snakelock anemone, such as the incognito goby, shrimps and Leach’s spider crabs. The tentacles of the anemone provide shelter and protection from predators. Human populations also use snakelocks anemones. For example, in southwest Spain and Sardinia it is a common dish, served marinated in vinegar and deep fried.
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. The Brent Goose Branta bernicla is of a similar size to a Mallard duck, making it one of the smallest goose species in the world. They are a highly social species and form strong bonds within the groups they live in. If you spot a group of Brent Geese, look out for the ‘compass’ goose – this is the leader of the group and will lead the way between foraging areas. Depending on the species of Brent Goose, individuals may have a dark or light belly, along with a dark head and body, with adults having a small white patch on their necks. They can be seen throughout the UK during the autumn/ winter months in marine, intertidal or wetland areas. Dark bellied Brent Geese. Photo Credit Emma Butterworth Migration Just like many other bird species, Brent Geese carry out an annual migration. They spend summer months breeding and raising chicks in the Arctic and migrate to Western Europe for more temperate winters. Generally, the individuals we get overwintering here in the UK are from Siberia. Due to these long migration routes and small body size, Brent Geese have a high food demand meaning they heavily rely on stopovers to refuel. Their most popular stopover sites tend to be Zostera marina meadows. Large numbers of Brent Geese have been spotted for several weeks each year in Izembek Lagoon (Alaska), lagoons in Baja California, the German/Danish Wadden Sea, the Golfe du Morbihan (France), British estuaries, and the White Sea (Western Russian Arctic). Diet Brent Geese are heavily herbivorous and mainly consume seagrass. They have relatively short necks and lack the ability to dive so can only reach plants at low tide or in shallow water. Interestingly, during breeding season the geese will consume a wide range of plant species but show a strong preference for Zostera species throughout non-breeding seasons due to the high digestibility and nutritional value compared to other options. They have been observed eating both the leaves and rhizomes of the plants. Importance of seagrass for Brent Goose populations As mentioned previously, Brent Geese rely heavily on seagrass during their migrations. This can be seen in population trends. In the 1930s, Zostera species across the North American coast were heavily affected by wasting disease and there was a significant population decline. At the same time, a steep decline in Brent Goose population was also observed on both sides of the Atlantic, with estimates ranging from 75 – 90% of populations lost. During the 1950s, there was a good recovery of seagrass beds in the areas previously affected, which was followed by a recovery of Brent Goose populations from around 15,000 to over 100,000. Similar smaller scale events like this have been observed, showing just how important healthy seagrass meadows are for species like the Brent Goose that rely so heavily on them. Are Brent Geese bad for seagrass restoration? It could be argued that Brent Geese are bad for seagrass and bad for seagrass restoration due to their consumption of the plants. However, there is a bit more to it than that. Seagrass provides services for many species, and a food source is one of those. Anecdotally, there have been instances where restoration has occurred only for geese to come along and eat all of the freshly planted shoots, which really isn’t ideal. In the scientific literature, there is mixed evidence about how much the geese will consume and how this affects the meadow’s health, which makes it difficult to quantify their impact. Some research notes that the percent the geese eat out of the whole meadow is actually quite small and a healthy meadow should have no issue recovering from any damage. The geese could even be useful in seagrass restoration. They tend to only be seen where food is available and as such are an indicator species for the health of an ecosystem. Like all birds, they are useful for their ability to spread nutrients and seeds through their faeces, helping to spread plant species more widely than they would on their own. Additionally, they are an important food source for predators such as foxes and raptors in their Arctic breeding grounds. Brent Geese, like any other species using seagrass, are carrying out behaviours that have evolved over thousands of years. Therefore, the question of whether geese are bad for seagrass restoration is not a straightforward one. What do you think? Sources: Ganter, B. (2000). Seagrass ( Zostera spp.) as food for brent geese ( Branta bernicla ): an overview. Helgoland Marine Research, 54(2–3), 63–70. https://doi.org/10.1007/s101520050003 Find out more the role that seagrass plays for migratory birds here.
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Sea hares are odd looking creatures. They are mostly soft bodied but have a small internal shell, which separates them from their close relatives – sea slugs. The sea hare gets it name from the two rhinophores sticking out from the top of the head as they look like the ears of hares. However, these appendages aren’t used for hearing, but for taste and smell. A sea hare’s favourite snack is seaweed, but they also eat seagrass. Interestingly, the colour of the seaweed species most prominent in their diet influences the colour of the sea hare individual, for example: diets made from mostly sea lettuce will lead to a green body colour and reddish-maroon sea hares will be eating mostly red seaweeds. Sea Hare on seagrass. Photo Credit Lewis M Jefferies A Sea Hare within an Orcadian seagrass meadow. Photo Credit Lewis M Jefferies When threatened, they can produce a cloud of ink which the sea hare can hide in to confuse predators. Scientists have found that this ink has antibacterial properties, thought to be useful in healing wounds and combating harmful bacteria. Additionally, they can produce a slime on their skin which makes the sea hare less tasty and puts predators off from eating it. Sea hare species can range from 2 to 70cm, but the ones found around the UK – Aplysia punctata or dotted sea hare – are on the smaller size of 7 – 8cm and can be found throughout the year in rock pools and shallow waters. They lay their eggs in long string-like structures attached to seagrass, with the seagrass meadow acting as a nursery environment when the eggs hatch. They are hermaphrodites, meaning individuals have both male and female mating organs. Despite this, they still reproduce with others, usually in a line with multiple individuals. Sea Hares in seagrass As well as seaweeds, sea hares will consume seagrasses too. As with many marine species, seagrass meadows provide an important nursery habitat. By attaching developing eggs to seagrass leaves, the eggs are protected from strong currents and predators, as well as providing a food source for newly hatched sea hares. Some species, such as the Phyllaplysia taylori or eelgrass hare, live solely on seagrass. Evidence has shown presence of sea hares increases seagrass productivity as a result of grazing on epiphytes on the leaves. A build-up of too many epiphytes will block the leaves ability to photosynthesize, so these little creatures can be very handy for us seagrass scientists! Sea Hare (with egg strings) on a blade of seagrass. Photo credit Lewis M Jefferies But do sea hares benefit society? Yes! They form an important part of diets around the world. For example, in Hawaii, people wrap the sea hare in to leaves and cook it in an underground oven, called an imu. In the Philippines, egg strands, known as lokot, are eaten raw with vinegar and spices. Samoa, Kiribati and Fuji also have sea hares as part of the traditional diet. Often it is women that will go out and collect the sea hares at low tide on mudflats and seagrass meadows and then sell them at markets, so sea hares have an important economic benefit to these societies too. For further information about how grazers such as the sea hare are beneficial to seagrass, look at this article.
