The destruction of aquatic ecosystems is a major issue facing conservationists globally – causes include microplastic pollution, acidification, global warming and over-fishing. The manufacturing team at NHBS have produced a series of new survey nets designed to help researchers gather data on microplastics and to sample plankton more efficiently. This blog describes the sea trials performed using our prototype nets to establish the optimal towing speeds and sea conditions as well as whether the nets worked effectively and were robust enough to withstand exposure to the marine environment.
Three new nets were tested – the Manta Trawl Net, which is designed to sample microplastics in calmer inshore waters and on rivers and lakes. The Avani Trawl Net, which is designed to sample microplastics in rougher, offshore environments and the Bongo Net (a pair of 300mm plankton nets joined in the middle and weighted with a depressor vane) which is designed to allow researchers to use two different mesh nets during a single trawl. Plymouth Sound was an ideal location, as we had both inshore and offshore designs to test and the breakwater provided us with easy access to both sheltered water and the open ocean.
The first design tested was the Bongo Net. The net performed very well. The sampling depth was easily adjusted by modulating the speed of the boat and the depressor vane kept the net level in the water. In our tests the Bongo Net performed best at towing speeds of between two and four knots.
Next, we tested our inshore Manta Trawl Net. The Manta Trawl Net is designed for microplastics sampling in calm inshore waters and on rivers and lakes. The Manta Trawl Net has a post box shaped aperture and twin ‘wings’ (manta wings) mounted onto the frame which serve to lift the net frame so that samples are efficiently collected at the top of the water column. This net was tested at a variety of towing speeds and performed best at speeds of between two and four knots.
The last net to be tested was The Avani Trawl Net. The Avani Trawl Net is designed for offshore microplastics sampling. The vertical orientation of the aperture of the net ensures that samples are collected from the top few centimetres of the water’s surface in slight to moderate swell conditions. To test this net, we ventured out beyond the breakwater where the swell was approximately 1-2m. The net stood upright and performed as expected at speeds of between four and eight knots when exposed to smaller waves of approximately one metre in height. When approaching larger waves, we found that the net had a slight tendency to cut into the side of the wave at speeds of between six and eight knots and that the net performed best at slightly lower speeds.
All of the nets functioned properly, and our haul included both microplastics and icthyoplankton (fish eggs and larvae). Both the frames and the nets also withstood the sea conditions well and we could find no faults with their design or build – all told a successful trial.
If you are interested in these nets look out for them in our 2019 catalogue, find them on nhbs.com, or contact us on firstname.lastname@example.org and we will send you more information as soon as it becomes available.
In Vaquita: Science, Politics, and Crime in the Sea of Cortez, author Brooke Bessesen takes us on a journey to Mexico’s Upper Gulf region to uncover the story behind the world’s most endangered marine mammal. Through interviews with townspeople, fishermen, scientists, and activists, she teases apart a complex story filled with villains and heroes, a story whose outcome is unclear.
In this post we chat with Brooke about her investigations in Mexico, local and international efforts to save the vaquita and the current status of this diminutive porpoise.
The vaquita entered the collective imagination (or at least, my imagination) when it became world news somewhere in 2017 and there was talk of trying to catch the last remaining individuals, something which you describe at the end of your story. Going back to the beginning though, how did you cross the path of this little porpoise?
I first heard about vaquita during a visit to CEDO, an educational research station in Puerto Peñasco, Mexico. I was enchanted to discover this beautiful little porpoise was endemic to the Upper Gulf of California, mere hours south of my home, yet saddened to learn it was already critically endangered. I still have the t-shirt I bought that day to support vaquita conservation. That was 2008 when the population estimate was 245.
The last update I could find was an interview in March 2018 on Mongabay with Andrea Crosta, director of the international wildlife trade watchdog group Elephant Action League. He mentioned there might be only a dozen vaquita left. Do you know what the situation is like now?
The last official population estimate was <30, but that was from 2016. With an annual rate of decline upwards of 50 percent, the number is surely much lower. If only we were able to watch the numbers go down in real time, we would all be forced to emotionally experience this sickening loss. But I think there is a (legitimate) fear that if an updated estimate revealed the number to be in or near single digits, key institutions might announce the species a lost cause and pull up stakes. If pecuniary support disappears, it’s game-over. Vaquita has graced the planet for millions of years—we cannot give up the battle to prevent its extinction so long as any number remain.
Once your investigation on the ground in Mexico gets going, tensions quickly run high. This is where conservation clashes with the hard reality of humans trying to make a living. Corruption, intimidation and threats are not uncommon. Was there ever a point that you were close to pulling out because the situation became too dangerous?
Truth told, my nerves were prickling from start to finish. The emotional fatigue was intense. But having witnessed the gruesome death of Ps2 [the designation given one of the Vaquita carcasses that washed up, ed.], I simply could not turn back. Then as the humanitarian crisis became clear and I was meeting families struggling to raise children in the fray, I was even more committed to telling this story. When courage wavered, I only had to remind myself of the host of social scientists, biologists, activists, and law-abiding fishermen working so bravely for the cause.
You describe a widespread indifference to the vaquita. I have the feeling a lot of this is cultural. Do you think a change in attitude can ever be effected? Or is the combination of poverty and the need to make a living completely at loggerheads with this?
I see two main obstacles to solving the vaquita crisis: corruption and poverty. In that order, because until local citizens can trust their military and police officers to rightfully enforce law, and until Pesca [Mexico’s National Fisheries Institute and its National Commission of Aquaculture and Fisheries, ed.] authorizes legal, sustainable fishing methods instead of providing loopholes for poachers, there will be no economic stability in the region. Money is pouring into the pockets of crime bosses while upstanding folks barely get by. Focused on either greed or survival, nobody has much capacity to care about porpoise conservation. That said, I do believe change can be effected. Several NGOs are already connecting with the communities in meaningful ways, and mind-sets are slowly shifting. If Mexico’s president-elect Andrés Manuel López Obrador, who goes by the nickname Amlo, manages to abolish corruption as he has promised to do, civic finances will balance out and efforts to care for vaquita will find better footing.
As the story progresses, more and more foreign interests enter this story. Sea Shepherd starts patrolling the waters, and Leonardo DiCaprio also gets involved, signing a memorandum of understanding with the Mexican president to try and turn the tide. What was the reaction of Mexicans on the ground to this kind of foreign involvement? Are we seen as sentimental, spoiled, rich Westerners who can afford unrealistic attitudes?
Since the majority of environmentalists working in the Upper Gulf are Mexican, and even Leonardo DiCaprio had the alliance of Carlos Slim, the socio-political divide does not seem to be so much between nationalists and foreigners as between fishermen and environmentalists. Fishermen who openly expressed distain for “outsiders” disrupting business meant Sea Shepherd, for sure, but they also meant scientists and conservationists from places like Mexico City, Ensenada, and La Paz. Some of the locals I spoke with or followed on Facebook did seem troubled by the amount of resources being spent on vaquita while their own human families suffered. They felt the environmentalists were not appreciating the strain and fear of their jobless circumstances. Then again, a good percentage voiced gratitude for the efforts being made to protect vaquita as a national treasure and seemed to feel part of an important crusade for their country and their community.
Related to this, the West has outsourced the production of many things to countries overseas and so many of us are far removed from the harmful impact that our desire for food and stuff has on the environment. Deforestation in the Amazon to graze livestock for hamburgers is one such long-distance connection that comes to mind. The vaquita has also suffered from the impact of shrimp trawlers. No doubt many who shed tears over the vaquita will happily gorge themselves on said shrimps without ever making the link. Do you think that globalisation has in that regard served to polarise the debate where wildlife and nature conservation is concerned?
Yes, this is a really important point. It’s easy to point fingers, but we are all complicit in the destruction of ocean life. Anyone who eats fish or shrimp caught in gillnets—or trawls, or longlines—is funding the slaughter of cetaceans and sea turtles and myriad other animals. It’s a painful truth. The root of the problem is that most of us don’t know, and don’t care to ask, where the seafood on our dinner plate came from. This is not intended to be accusatory, as I, too, am finding my way in this era of culinary disconnect. I just know the first step is to quit pretending we are bystanders.
One side of the story I found missing from your book was that of the demand for totoaba swim bladders in China. I imagine it might have been too dangerous or time-consuming (or both) to expand your investigation to China as well. How important and how feasible do you think it is to tackle the problem from that side? Without a demand for totoaba bladders, the vaquita wouldn’t face the threats of gillnets after all.
I think it’s imperative to attack the totoaba trade from the consumer side, with the goal of systematically eliminating the demand for swim bladders. As for feasibility, I’m less confident. Time and distance prevented me from effectively researching the situation in China, but from what I’ve read, the cultural, political, and economic trappings there are just as complicated as they are in Mexico. I’m pleased to know efforts are underway. It also must be said, though, that ending the totoaba trade is not a sure-fire resolution for vaquita because fishermen in the Upper Gulf traditionally use gillnets for a range of legal fish.
With the book now written, are you still involved in efforts to protect the vaquita?
Knowing what I know now, it’s unthinkable to walk away from vaquita. I was down in San Felipe last month, exchanging summer c-pods and catching up on the latest news. Everyone is nurturing the flicker of hope that Amlo will take action to save his national marine mammal by cleaning up the corruption that has stymied vaquita conservation.
With their horn-shaped cephalic fins and large, gaping mouths, manta rays have long been the source of mariners’ myths and legends. Today, we know much more about these curious creatures, although many features of their lives and behaviours remain a mystery.
Marine biologist and co-founder of the Manta Trust Guy Stevens has spent many years researching mantas in an effort to understand their lives and to promote conservation practices that will ensure their continued survival. In Manta he has joined forces with National Geographic photographer Thomas Peschak to create a visually stunning and informative tribute to these animals.
To coincide with the re-release of the book, we recently spoke to Guy about his work with Mantas and the conservation challenges that they face.
Your life as a researcher and CEO of the Manta Trust must be incredibly varied and exciting. I’m curious what a typical day in the life of Guy Stevens looks like. Or, if a ‘typical’ day is unheard of for you, can you describe a recent day for us?
My days tend to be dictated by where I am. When in the field I am usually diving or freediving with manta rays on a daily basis, collecting data or guiding tourist expeditions. However, increasingly the majority of my time is spent on my computer behind a desk responding to emails, having Skype calls, writing papers, applying for grants and managing an ever increasing manta team.
Setting up an NGO must require an immense amount of work and passion. What did you find most challenging about the process and, as an extension of this, what advice would you offer other conservationists who are hoping to travel a similar path?
The most challenging part of the process, which still remains the main challenge today, is ensuring there are funds to enable the charity to carry out its mission. My advice to anyone wishing to follow a similar path would be to ensure you diversify your revenue streams.
The work conducted by yourself and other researchers around the world has contributed a huge amount to the body of knowledge about manta rays. What do you think are the next big questions that need to be addressed and how do you think new technologies (e.g. satellite and acoustic tagging / genetic techniques) will contribute to these?
From a conservation perspective one of the next big focus areas is to try and quantify the extent and impact of bycatch fisheries on the high seas (such as purse seine tuna fisheries) to manta rays and their close relatives, the devil rays; how many are being caught, which species, where, when and how many survive release after capture? Using post-release mortality tags can help us to estimate how many of the rays are likely to survive being captured after release, while the implementation of better management practices can hopefully reduce bycatch.
It is clear from your book that the problems facing mantas are incredibly complex and, as such, will require complex solutions. The final message I took from your book, however, appears to be one of hope. What significant changes would you like (or hope!) to see happen within the next five years in the arena of manta ray conservation.
I would like to see a world shifting away from industrial fisheries which employ unsustainable fishing practices; such as drift nets, long-lines, gill nets, etc. The oceans are rapidly being depleted and we need to protect much greater areas of this common resource from fishing if we want to stand any chance of safeguarding the world’s charismatic species like manta rays from extinction in the next few decades.
Finally – and I appreciate that you must have hundreds to choose from – is there a single encounter with a manta ray that really stands out in your memory and that will stay in your heart forever?
Yes, certainly the encounter which stands out the most is the one I describe in the book with the manta Slice, who I rescued from fishing line back in 2008 in Hanifaru Bay….there are lots of detail on this encounter in the book and here’s a link to the story on our website (although it is a bit outdated now); http://www.mantatrust.org/amazing-experiences-entangled-manta-rescue/
Catching a glimpse of a whale or dolphin whilst visiting the coast is a uniquely memorable experience and a few hours spent whale and dolphin watching is fun for all age groups. Plus, your sightings can really make a difference and will add to the growing body of survey data collected for the UK coastline.
Keep reading for some tips on when and where to watch whales and dolphins, how to get started and where to report your sightings.
When and where should I watch cetaceans and what am I likely to see?
The best time for spotting cetaceans is between April and October when visitors to our coastal waters are at their highest. Some areas are undoubtedly better than others for catching a glimpse of these elusive animals: Devon, Cornwall and Cardigan Bay in Wales are good places to go, as well as the coasts of northern Scotland.
Twenty-nine species of cetacean have been recorded in UK waters, and some areas of our coastline are home to permanent populations of dolphins. The most commonly reported species are bottlenose dolphins, harbour porpoises and minke whales, although rarer visitors have included killer whales, humpback whales and striped dolphins.
Of course, cetaceans aren’t the only things you will see. Keep your eyes peeled for seals too and enjoy the seabirds and beautiful views at the same time!
How do I get started watching whales and dolphins?
For most people, watching cetaceans from the land (rather than from a boat) will be the most convenient and economical option. Any place where you can sit comfortably with a good view of the sea will suffice, but if you can make your way to a cliff top then this will provide a better vantage point. Calm, overcast days tend to be the best for spotting cetaceans as the combination of swell, choppy waves and surface reflections can make fins all but impossible to see. For the same reason, the hours following dusk and prior to dawn are the best times of day to go.
A watch is conducted by scanning the surface of the water with the naked eye, switching to binoculars periodically or whenever you notice a disturbance at the surface. As soon as you see something that may be a whale or dolphin, concentrate your binoculars in that area, making sure to scan a little way around in case it surfaces again nearby. Another good technique is to look out for seabirds circling or diving as this may indicate cetaceans feeding just below the surface.
Any binoculars (or a scope and tripod) can be used for sea watches. If you are looking for binoculars specifically for this activity, however, make sure to go with a model that has a large objective lens diameter as this will improve the light transmission and will help with viewing in lower light conditions.
For researchers studying marine mammals, items such as thermal imaging scopes and hydrophones are useful additions to the surveying toolbox and will allow them to find and identify cetaceans in a greater range of conditions as well as enabling more detailed investigation of behaviour.
Check out the NHBS website for a great range of binoculars and scopes, as well as other handy field kit such as waterproof clipboards and notebooks. Also have a look at these two field guides to help with identifying whales and dolphins.
Following the acquisition of EFE & GB Nets earlier this year, NHBS now manufactures a wide range of plankton nets at our workshop in Devon. Nets are available with an opening diameter of 250mm, 300mm or 500mm and with mesh sizes ranging from 10µm to 500µm.
250mm and 300mm diameter nets
250mm and 300mm diameter nets have a stainless steel frame to which a 500mm long bag is attached. They are supplied with a harness and seven metre long towing line which can be used to tow the net behind a boat or from a suitable bank or jetty.
The standard cod end is fitted with a filter in the same mesh size as the main part of the bag. However, various alternatives can be selected at the time of ordering. Options include a clear extension tube, collecting bottle, tap valve or large filter fitted in place of the standard filter. It is also possible to have weight loops added to the end of the net (weights not included) or a stainless steel swivel to be used on the harness in place of the standard nylon ring.
The heavy duty upgrade uses heavy duty nylon for the net collar and cod end collar and also includes fully taped seams.
500mm diameter nets
500mm diameter nets have a stainless steel frame and 1900mm long bag and a three point harness with swivel connector. All seams are reinforced and the collar is made from industrial nylon for added strength and durability. The cod end of the bag is fitted with a heavy duty screw-on filter in the same mesh size as the bag. This net is not supplied with a towing rope and so users will need to supply their own rope or chain which can be fitted to the harness.
As with the smaller plankton nets, various adaptations are available in order to create a net which is suited to your sampling needs. A flexible cod end extension allows a greater sample volume to be collected and also lets you connect a different filter type. A replacement cod end cap provides a closed ended option and results in a sample size of 700ml and a quick release bag is ideal for collecting fry or elver or for when a rapid changeover of bags is required.
Net bags and the educational plankton net
As well as standard plankton nets, we also stock a range of plankton net bags designed to fit onto the professional hand net frame. These fit onto the frame in the same way as the standard hand net bags, and have a detachable screw-on filter in the centre. An educational plankton net with 150µm mesh is also available for school use or for those who require an economical net for trial sampling.
We also learned about the importance of citizen awareness in the Global Fishing Watch project. This amazing new scheme uses satellite data to make global issues of overfishing much more transparent, as well as making huge quantities of fisheries science data available to researchers.
A full-colour identification guide to members of the genus Carcharhinus, notably difficult to distinguish by species.
We are always really impressed by the books published by Verlag Friedrich Pfeil, and this is no exception. The excellent drawings by master technical artist Weber, carefully indicate the relevant anatomical distinctions between the 33 species covered, and the research is immaculate, providing all the facts required for identification. In addition there is plenty of information on the biology and natural history of the genus, plus a glossary of technical terms and many maps, tables and plates.
As well as appealing to marine biologists and shark enthusiasts, this volume has further application in the fields of fisheries, diving and other aquatic sports – in other words for anyone to whom positive species identification would be relevant.
It is hoped that this book will go some way to providing clearer records about threatened shark populations.
Dr Matthias Voigt studied marine biology at the University of Rostock (2000-2004), received his PhD from the University of Karlsruhe and now works at the University of Konstanz in the Department of Biology, Human Environmental Toxicology Group. He has had many experiences with sharks while diving, and as a member of the German Elasmobranch Society (D.E.G.), he tries to impart his experience, knowledge and fascination with sharks to the general public for increased understanding and protection.
Dietmar Weber is likewise a member of the D.E.G., and has a passion for the lifelike portrayal of animals, an art form which he has perfected over the last forty years. He is currently focused on sharks, skates and rays and his work has been featured in many publications. A graduate professional Technician for Biology i.e. Ecology, he has worked at the Research Institute for Forest Ecology and Forestry of Rhineland-Palatinate in Trippstadt since 1989.
A few weeks ago, I attended the 14th Biennial EURASLIC Meeting. EURASLIC is the European Association of Aquatic Sciences Libraries and Information Centres. This year’s meeting on the topic Caught in the “fishing net” of information was hosted by Cemagref, in Lyon, France. The weather was lovely, the food excellent, and it was a joy to spend a few days in the company of extremely knowledgeable librarians from many countries.
Among other things, I talked on the topic of hard-to-find books in Marine Biology (here is the Powerpoint Presentation of my talk). At NHBS, we have great experience in identifying and cataloguing specialist titles published by small publishers, and we know how much effort is involved in the process. In passing the information on to libraries through our Monthly Catalogue, our online catalogue, and topical newsletters, we hope to make these publications known to a much wider audience. Every week, we see new books that are not available to buy from mainstream booksellers.
Some examples of titles that should be on the shelves of every marine biology library in Europe, but are not always known to librarians, include:
We are always struck by just how varied and inspiring is the range of books we come across at NHBS, and challenged to give stand-out books their due. To this end, we’ll be highlighting a book every week here on the Hoopoe, as our Book of the Week. All books are chosen by us – no publisher’s endorsements! Simply our “what? why? who?” guide to the superb scientific texts, monographs, field guides or natural history books that we think you need to hear about…
This is an introduction to the most important and most common taxa present in the plankton. It is intended as a guide for students, marine researchers and even the interested lay person, and contains 930 micrographs (nearly three-hundred more than the first edition) allowing the identification of numerous common species, now including some from Mediterranean waters.
With its huge number of colour photographs it complements, and is recommended as a photographic supplement to, the illustrations of more comprehensive taxonomic keys – helping students and others without extensive taxonomic experience to gain a better grounding in plankton identification.
Prof. Dr. Otto Larink is a zoologist. During annual courses at the Biological Station on the isle of Helgoland in the German Bight since 1963 and during various visits at European coasts he has observed the diversity of plankton organisms and documented them with many micrographs presented here.
Prof. Dr. Wilfried Westheide is also a zoologist specialising in systematics and morphology of invertebrates, especially annelids.
This book provides a comprehensive introduction to the biology and ecology of plankton and describes its use as a tool for monitoring water quality. All the major freshwater and coastal phytoplankton and zooplankton groups are covered and their associated environmental issues are discussed. A chapter on best practice in sampling and monitoring explains how to design, implement and conduct meaningful phytoplankton and zooplankton monitoring programs in marine and freshwater habitats, as well as how to analyse and interpret the results for effective management decision-making.