We Mainely talked about lobsters…

Earlier this summer I was lucky enough to attend the 11th International Conference and Workshop on the Biology and Management of Lobsters (or the ‘ICWL’, by its much-needed abbreviation) which was held in Portland, Maine, the most north-easterly of the United States. The conference occurs every 3-4 years and, despite its somewhat obscure-sounding name, is a big deal among marine biologists whose research is based on, or applies to, lobsters; the 10th and previous edition of the conference had attracted 182 delegates from 21 countries. Any thought that such a turnout might have been a consequence of the conference being held in Cancun on Mexico’s beautiful Caribbean coast was quickly dispelled in Portland, where even more lobster nerds gathered despite the more variable climate! Such a large community of scientists involved in research on lobsters is perhaps best rationalised with the accompanying knowledge that, globally, various lobster species are annually worth almost US$3,000,000,000 (that’s three billion bucks!) as a seafood commodity. The Hatchery and our collaborations in ongoing European lobster research were particularly well represented. Along with my colleagues from Padstow, Carly Daniels and Dom Boothroyd, there were: Tom Jenkins, a PhD student from Exeter researching the genetic connectivity and population structuring; Corey Holt, another Exeter PhD student investigating the microbiome and health of lobsters at CEFAS; Michelle Pond, a CEFAS scientist investigating histology and disease as part of our ongoing Lobster Grower 2 project, and; Grant Stentiford, an expert pathologist at Cefas who also happens to Chair the Hatchery’s board of scientific advisors.

After something of an ordeal getting there (including an unscheduled layover at Newark airport which soon offset our excitement at the fine views of the Empire State Building and Statue of Liberty), we settled in for the conference kick-off on the first of five days of research talks. Some sort of bigwig is often invited to launch conferences and the 11th ICWL was no exception, where Senator Angus King, the state’s political representative. What was exceptional though, was Senator King’s speech, which was funny, insightful, and displayed an intimate knowledge of climate change science, a subject of obvious concern to his region given the temperature-linked collapses in the hugely valuable American lobster stocks in warmer areas to the south. Jelle Atema, the only surviving delegate from the 1st edition of the conference, held in Perth in 1977, was also a fantastic choice as the opening plenary speaker, providing an overview of a fascinating career in sensory ecology and American lobster mating behaviour. Jelle showed a video of male lobsters fighting for dominance by locking claws in a kind of first-to-submit squeezing war! Interestingly, he found that once a hierarchy had been established through these battles, it is then maintained without any further conflicts, because weaker males can literally be smell the presence of dominant males, and they remember to keep clear of them. Pretty clever for a close relative of the woodlouse…!

The week’s talks were split into 17 themed sessions. Diseases & Parasites was first up, with Welsh wonderkid Charlotte Davies stepping in to co-Chair a session in which fellow countryman Corey demonstrated how tank- and sea-reared juvenile lobsters differ in internal microbiota, and Michelle showed fascinating examples of cells being torn apart from the inside out by a mystery ailment she is working to identify. Over in the Reproductive Biology stream, French researcher Martial Laurans showed the results of a mark-recapture survey of egg-bearing females in Brittany, with as many lobsters moving 50-100km as stayed within the area of release, suggesting that emigration is either greater than previously thought, or perhaps varies spatially between populations. Geir Dahle then showed the remarkable pattern of lobsters in his native Norway to reach reproductive maturity at smaller sizes with increasing latitude, down to a tiny 55mm carapace length in the sub-Arctic fjords. He attributes this to the variation in light levels, and it seems to fit a tentative hypothesis I made in a previous meta-analysis of female fecundity; that maturity and clutch size may be driven by age rather than bodysize. Day two’s plenary was Paolo Prodohl, the Brazilian geneticist at Queens University, Belfast. Paolo presented findings from over a decade of research on European lobster genetics, including from his ongoing assessment of the impact of v-notching in Northern Ireland, which he evaluates by assigning newly-sampled lobsters to parents via genetic markers. This was of particular relevance to me and others at the hatchery, as we plan to use this parentage-based tagging technique to similarly assess the impact of stocking releases in future. As ever, Professor Prodohl’s talk contained findings of potentially huge significance to the management and conservation of lobsters – such as the assertions that larger females contribute more recruitment than smaller females, that up to 20% of the current stock derives from egg-bearing females returned to the sea in the first year of v-notching, and that landings have doubled since the scheme began in 2003 – but a sect of delegates remain frustrated that their huge appetite to see this work published in academic literature remains, as yet, unfulfilled. Hopefully the conference proceedings, to be published in the Bulletin of Marine Science next year, will finally address this. Later, Kenzie Mazur presented results of her modelling work on American lobster stocks which also showed the massive difference v-notching can make to stock abundance; had no females been v-notched since the 1980's, landings would be expected to shrink to only ~7 million tons per year, compared to the vast productivity of the current fishery, with landings in excess of 100 million tons, when more than half of berried females are returned to spawn.

Further genetics-based talks were forthcoming from Laura Benestan and colleagues from Quebec, whose resources for evaluating and interpreting spatial structuring and evolutionary adaptation of lobster populations using genomic techniques is the envy of us researchers across the pond. As well as thermal niche adaptation and current-mediated larval dispersal, Laura recently identified sex-linked loci as a driver of genetic diversity in American lobsters, highlighting the importance of controlling, or at least recording, sex ratios in population genetic studies. Tom Jenkin’s is attempting to close this transatlantic knowledge gap with a population genomic approach in European lobsters. His work, still in its developmental phase, has supported my previous finding that divergence may exist between stocks in the semi-enclosed seas moving toward the entrance of the Baltic, and those around more open Atlantic coasts. This essential resource for European lobster research needs as broad a sampling effort as possible, so if you think you can help by providing tissue clips from European lobsters in your area, please get in touch with him at t.l.jenkins@exeter.ac.uk . Other notable ecological research on European lobsters was presented by Ellen Sofie Grefsrud, who found that lower seawater pH increased the planktonic duration, suggesting that future ocean acidification may increase the window for which pelagic predation will inhibit recruitment.

The Kiwi biologist and science communicator par excellence (https://vimeo.com/116966847 ), Gaya Gnanlingam, reported results of her studies into the reproductive potential of large spiny lobsters in the Caribbean. It has long been known that, as lobsters increase in size, they produce more eggs, but many management organisations and fishers have been reluctant to introduce maximum landing sizes to compliment the minimum sizes widely used. This reluctance has generally stemmed from notions that larger lobsters may breed less frequently, that larvae may be of lower viability, and that very large lobsters may reduce overall population abundance by outcompeting smaller lobsters. However, Gaya’s studies comprehensively disproved these misconceptions, lending support to the growing number of biologists advocating a slot-size harvesting regulation to manage stocks like lobsters, for which capture processes enable high post-release survival. Such a move would act to ease growing concerns over fisheries-induced evolution, whereby a variety of marine species are being found to be reacting to the considerable selection pressures of intensive fishing in ways that may be counter-productive to the sustainability of seafood stocks. An example of this was characterised by research from Raquel Goni, David Diaz, Sandra Mallol and Ana Munoz on a spiny lobster stock near Mallorca which is protected from fishing – they found that the size at which lobsters begin breeding has been getting bigger since fishing ceased, and the pressure of size-selective harvesting was removed. This study, based on results collected over two decades, highlights the importance of long term datasets, and of marine reserves in allowing us to observe what a species biology looks like in the absence of direct human interference. Nevertheless, Michael Roach later argued that data collected on European lobsters in the North Sea suggest that a rotational designation of no-take zones is a more effective fisheries management tool than a fixed protected area.

By midweek we’d enjoyed a couple of enjoyable evenings exploring the pristine streets of Portland, and it was time for a day focussed on Industry. Carly and I both gave well-received talks in the Aquaculture session, inclusive of tank- and wild-based operations for both full grow-out and fishery restocking. Carly gave an update on our ongrowing project (www.lobstergrower.com ), while I presented the results of a semi-theoretical trial of parentage-based tagging which suggest that assignment of recaptured lobsters to parent-pairs, rather than mothers alone, can dramatically improve analytical accuracy. The session was sparsely attended, a shame particularly given the scope for aquaculture interventions to improve the supply of wild and farmed lobsters, and the vision of Maine lobstermen, 90% of whom believe that diversification into shellfish or seaweed culture will be required within the next 5 years, according to local biologist Caitlin Cleaver. Clive Jones and Greg Smith gave updates on the progress in their Australian hatchery of culturing several spiny lobster species and understanding their natural recruitment; Smith has quantified that 1 in 50 larvae reared in the hatchery survive to adulthood, an improvement of 100,000x their prospects in the wild! Meanwhile, across the Tasman Sea, scientists from the Cawthron Institute, including Rob Major, Alaric McCarthy and Kevin Heasman, provided insights into their attempts to culture the larvae and study the lifecycle of deep-water New Zealand scampi. An afternoon tour of local processors Ready Seafood put the scale of the American lobster fishery into context – Ready is just one company in just one town in just one state within the lobsters range, but they handle 5000 tonnes of lobsters each year, about the same volume as equates to the entire commercial catch of European lobsters!

Climate scientist (and surely the youngest Professor in academia) Malin Plinsky of Rutgers University gave a super plenary on the effects of ocean warming on fish biology. Plinsky’s meta-analyses suggest that, although many marine species abundance declines as a consequence of climate-related changes, most of those whose ranges encompass open coasts and oceans do seem to be adjusting by shifting towards areas with the temperature regimes they prefer. Of particular relevance to our hosts in Maine was whether coastal communities would be able to adjust as quickly – at the moment the lobsters are moving to more northerly latitudes, with harbour towns towards the south of the range suffering badly as their fisheries, and livelihoods, disappear. For fishers in Maine, whose income is almost solely reliant on the catch of lobster (and herring for pot bait), this is a real worry. Alongside climate change, the other major topic of man-made concern at the conference was the escape or release of American lobsters into transatlantic waters, where some researchers have argued they have the potential to become invasive and wipe out native species. Huge volumes of lobster from New England and Canada are imported alive into Europe every year and although it is illegal to do so, many end up back in the sea, with even well-meaning animal lovers contributing to a potentially massive conservation problem (http://www.dailymail.co.uk/news/article-3137547/Buddhists-bought-2-000-lobsters-crabs-set-free-foreign-crustaceans-eat-local-sealife.html – sorry, I feel dirty even linking to the Mail but none of the other papers seemed to pick up this story…). This is a worry as American lobsters bring a host of potential threats to European conspecifics, including disease, competition and hybridisation. The University of Hull’s Magnus Johnson has been a vocal advocate of a mooted EU import ban (https://theconversation.com/ban-imported-american-lobsters-before-they-take-over-europe-66644 ), so it was pretty brave of him just to turn up in Maine! However, his talk in the US carried a slightly more conciliatory tone – instead of urging for an outright ban, Johnson urged the comparatively large and well-resourced community of Stateside lobster researchers to take the issue and their local industry’s responsibility seriously, and assist European collaborators in urgent research to assess the risks. This approach was sensible from a diplomatic perspective, but has considerable conservation merits, too; an outright ban on live American imports would arguably create and even greater conservation problem for European lobsters, whose stocks would inevitably be vulnerable to chronic overfishing should their value soar as a consequence of a supply deficit.

The talk I found by far the most eye-opening was delivered by plenary Professor Bob Steneck, who lives and works an hour up the Maine coast from Portland. At 63, Bob has a wealth of experience and is only too happy to share it for the benefit of the next generations of scientists, who are unlikely to share his luck in having access to a submarine or ethical approval to tether lobsters to concrete blocks in order to observe what eats them! Bob showed how, over the past 60 years, lobster abundance has risen as the diversity and abundance of fish was drastically reduced. The most recent spike in lobster landings also follows the advent of a lucrative fishery for urchin in the 1990s, whose removal was followed by an expansion of kelp beds, a preferred habitat of lobsters. And then there is the vast volume of fish used as trap bait – >100,000 tonnes of herring a year; the sooner Hull student Tom Evans comes up with a sustainable artificial alternative, the better! Most American lobster traps have escape gaps, so immature animals can stop in for an easy feed whenever they fancy. Recent studies have estimated that trap bait is a significant component of lobster diets, comprising up to 80% of a lobster’s sustenance in some areas. All of which conflicts the notion of Maine’s lobster stock being a ‘natural’ system; in Bob’s words, “we have created a domesticated environment for lobsters – we’ve wiped out all the predators and we’ve fed them!” Although I was aware of this feedback between fishing activities and seafood populations, this really resonated with me and led me to question some of my most fundamental assumptions. For example, it seems a given that reducing fishing pressure should increase stock abundance, but American lobster stocks might actually experience mass mortality through starvation if all trap fishing were to cease. And it significantly blurs the lines between the wild, natural seafood, which I’d always considered to be the best choice for the ethical consumer (providing it had been captured from sustainable stocks and without wider damage to the ocean ecosystem), and that reared via aquaculture. It turns out that reasons commonly given to advocate the avoidance of aquacultured fish, such as the inefficient use of edible proteins to rear a more valuable species, apply equally to wild stocks in the case of American lobsters. So rather than a truly wild population, perhaps it is better to think of intensely fished lobster stocks as the oceanic equivalents of cattle openly ranched without fences. Thinking about this paradox, it seems more accurate to conclude that the more intensively seafood is produced, the further away from a ‘natural’ product it is, regardless of whether it has lived in a farm or the wild.

These thoughts were still with me during the presentations which closed the conference, as each session Chair was invited to summarise the highlights from their session and review general progress in their research field. While every other Chair was clearly enthusiastic about the pace of development and quality of research being done in that sector, it was notable that the Aquaculture chair, Professor Andrew Jeffs of the University of Auckland took a different tone, instead choosing to highlight how painfully slow progress in aquaculture innovations has been. He said that the researchers actively working to innovate and solve issues in aquaculture were doing an excellent job, but that in general the field was criminally under-resourced considering the perilous status of many wild fisheries and ecosystems, and the potential for research in aquaculture to boost sustainability and productivity of the lobster seafood supplies and the coastal communities currently relying on their economic value.

I finished the week exhausted, but having thoroughly enjoyed my second experience of the ICWL. It was nice to rekindle a few friendships, make a whole lot of new ones, and feel a little more established as part of this unique and vibrant international research community. The countryside of Maine, the city of Portland, and the friendly people who inhabit both are well worthy of a visit should you ever get the chance. And though it can seem hard to justify a long-haul trip in which every evening was spent propping up the bar with my fellow ‘lobsterologists’, I promise it was strictly business, and we never deviated from talking lobster science! How many days left is it until we go down under to Perth for the 12th ICWL in 2020?!?!