Looking back in awe: spectacular advances in the marine biodiversity toolbox to support sustainable oceans

Abstract

My 40-year career has spanned a rapid acceleration in interest and technical capacity to assess and understand marine biodiversity, and its role in Earth’s life support system. These advanced technologies, including modeling and statistical tools, observational and mapping capabilities, in situ experiments and measurements, genetics, lipid and stable isotope markers, and communication and collaboration tools, all offer new opportunities for major scientific advancement to a degree not previously available. These tools can enhance marine conservation efforts toward greater ecological and environmental sustainability. Drawing from three interlinked themes of biodiversity drivers, ecosystem functioning, and population connectivity, I summarize changes in my own thinking on ocean science, the top 10 lessons learned along the way, and the potential applications of new technologies to societal challenges.

Introduction

When ICES editor Howard Browman, an old friend from McGill graduate school days, invited me to write a Food for Thought piece, it challenged me to ask how I got here and what I have learned that I would like to share. “Looking Back in Awe” refers to how we operated at the beginning of my career and how far technology has advanced (Table 1). Some of the ways we worked back then bring a smile to my face. From the appearance of “lunchbox computers” when I was an undergraduate that ran simple programs from a floppy disk to augment punch card mainframe computers to typewritten letters through snail mail, we advanced scientific knowledge but did so using a (sometimes) laughably simpler and less efficient toolbox than what we have available today. Below, I describe the (near) random walk and lessons learned along the way, a few bumps in the road, and the many opportunities afforded to me that now create opportunities for early career researchers who share a passion for the ocean and especially marine biodiversity.

Lesson 1—the undergraduate experience

Some 40 years ago, when I was an undergraduate, biodiversity (generally called “diversity” at that time) was a bit of a fringe topic among a modest subset of natural scientists. Indeed, Gene Gallagher relayed a story of a conversation with Pierre Legendre in the 1990s where Legendre suggested diversity was a bit passé, but (happily) Gallagher convinced him otherwise, and Legendre would go on to publish important diversity papers with Gallagher (Legendre and Gallagher 2001) and separately (e.g. Laliberté and Legendre 2010, Legendre and De Cáceres 2013). Still, three “discoveries” would help to set my career path in this biodiversity research, which would eventually become more mainstream. The first discovery resulted from my walking into Richard (Dick) Haedrich’s office in Memorial University of Newfoundland in search of a potential honors supervisor. He took me down the hall and showed me a 5-gallon glass pickle jar of the most bizarre and spectacular animals I had ever seen—a collection of deep-sea fishes that would eventually become my honors dissertation, which documented the absence of clear depth zonation in fishes on the Newfoundland continental slope (Snelgrove and Haedrich 1985). The second “discovery” occurred when Haedrich encouraged me to take his graduate Deep-Sea Biology course, despite my lowly undergraduate status. The course examined a newly published book in a series called “The Sea” (Rowe 1983), focusing on the deep sea, and Haedrich asked me to review a chapter on deep-sea diversity (Rex 1983), which set the hook; I was enthralled with marine biodiversity. The third (and truly mind-bending) discovery, which I learned overhearing a hallway conversation with an undergraduate professor, was the discovery of hydrothermal vents, an entirely new ecosystem (Corliss et al. 1979) fueled by chemosynthesis and symbioses rather than sunlight (Cavanaugh 1983).

Lesson 1: Talk to your mentors and find out what’s new and exciting.

Lessons 2–4—the graduate experience

It did not even occur to me, a naïve undergrad, to look outside Canada for graduate school, and few Canadian scientists were working in deep-sea ecosystems at that time. I therefore turned my attention to coral reefs, another hyper-diverse marine ecosystem attracting attention (e.g. Connell 1978). John Lewis, a coral reef biologist at McGill University, offered me a position in his lab to work on the degraded reefs in Barbados through their Bellairs Research Lab. This experience gave me a taste of tropical diversity, where I documented how nutrient loading and coral morphology influenced associated cryptofauna (Snelgrove and Lewis 1989, Lewis and Snelgrove 1990). But my hunger for the deep sea persisted, so I wrote letters to the leading deep-sea biologists in the United States. Lewis, a kindly man, told me I could try, but these were busy people who probably would not write back. Happily, he was wrong, and they all took the time to respond. Keep in mind this was well before email, and a letter was a significant time investment! These responses included the break of my lifetime, a letter from J. Frederick (Fred) Grassle, a senior scientist at Woods Hole Oceanographic Institution (WHOI), encouraging me to apply to work in his lab. Grassle had published pivotal papers on deep-sea diversity (Grassle and Sanders 1973, Grassle et al. 1975, Grassle 1977, 1985) that made him a global leader in marine ecology. Perhaps aided by my McGill credentials, an unflagging interest in deep-sea diversity, and a strong support letter from Haedrich (a former WHOI scientist), Grassle accepted me, and in the summer of 1987, I found myself loading up my belongings in my old 1978 VW Rabbit and giddily driving to Cape Cod to begin a PhD program in the M.I.T./Woods Hole Oceanographic Institution Joint Program.

Lesson 2: Chase the opportunities that excite you, and don’t sell yourself short.

I was enthralled by the Cape Cod landscape and the beehive of ocean science in Woods Hole. A semester at M.I.T. was amazing and humbling (many smart students!); pep talks from Cheryl Ann Butman (now Zimmer), who Fred had enlisted as my co-supervisor, and Fred would help me squeak by in a required biochemistry class I did not enjoy. Once back at WHOI, life improved dramatically. Oceanography lectures were available daily, and Grassle would host meetings of global leaders in marine biodiversity such as Carlo Heip, Ramon Margalef, Alisdair McIntyre, Tim Parsons, and others (e.g. Grassle et al. 1991), and he made sure I met them all. Coral reef and deep-sea biologists at the time were interested in biodiversity, but it was still more of a curiosity-based science. The situation changed with the publication of Biodiversity (Wilson 1988), which captured broad interest in biodiversity, and a pivotal paper that projected 10 000 000 species in the deep sea (Grassle and Maciolek 1992) and set the science community abuzz (e.g. May 1992).

Opportunities abounded at WHOI to access leading-edge technologies, including the submersibles PISCES, ALVIN, MIR, and Johnson-SeaLink to undertake in situ experiments and the use of laboratory flumes to mimic bottom flows. Cheryl Ann instilled her interest in hydrodynamics (Butman 1989) and larval ecology (Butman 1987), which would become a core element of my thesis work. Cheryl Ann was working closely with Judy Grassle on larval habitat selection (Butman et al. 1988), and I suddenly had a dream team advisory committee, where Fred championed big ideas and Cheryl Ann and Judy shared thoughtful insight on experimental design, analysis, and the art of clear scientific writing. Collectively, they instilled in me the value of interdisciplinary science and the power of collaboration. My deep-sea work melded Grassle’s interest in ephemeral patches and deep-sea biodiversity (e.g. Grassle and Sanders 1973) with Butman’s interest in larval settlement and hydrodynamics. My shallow-water field experiments showed that settlement of most local species depended largely on near-bed hydrodynamics (Snelgrove 1994), a finding consistent with flume experiments showing passive entrainment of settling larvae but limited selective capacities that vary among species (Snelgrove et al. 1993). Numerous dives in the Johnson SeaLink submersible in deep waters off St. Croix would shape my view of the deep sea and enable my first deep-sea experiments, which showed that different types of organic matter yielded different responses by early seafloor colonizers, potentially contributing to the hyperdiversity of deep-sea sediments (Snelgrove et al. 1992, 1994, 1996).

Lesson 4: Draw on the core strengths of your mentors to get the most from their experience.

Lesson 5—the emerging toolbox

I assumed that the toolbox available to me at that time, with some modest improvements, would serve me for the rest of my career. Wrong. I would spend the next 30 years finding new collaborators and new tools.

Lesson 5: Science advances rapidly and brings new tools and applications that offer opportunities to accelerate learning and discovery.

Lesson 6—the postdoctoral experience

A postdoctoral fellowship starting in 1993 with Fred and Judy Grassle, then at Rutgers University, should have tipped me off that the 1990s would see major advances in ocean science. Fred, always brimming with ideas (Snelgrove et al. 2009), championed the need for more frequent observations in the ocean, where most sampling at that time used ship-based snapshots of ocean processes and a modest set of sensors deployed on moorings. This need inspired him to spearhead the development of the Long-term Ecological Observatory on the New Jersey coast (LEO-15), which involved running a fiber-optic cable to the coastal shelf to deliver power to ocean instruments and send data back to shore (von Alt and Grassle 1992). Fred also championed the benefits of data sharing, and launched the Ocean Biogeographic Information System (OBIS, now Ocean Biodiversity Information System) (Grassle and Stocks 1999), which would enable numerous global-scale marine biodiversity studies (e.g. Tittensor et al. 2010, Webb et al. 2010).

During this period, Fred lamented the lack of a biodiversity initiative akin to the Joint Global Ocean Flux Project (JGOFS), despite a clear need identified by a National Research Council (1995) report that Butman had co-led. But during a visit to Woods Hole, Fred met with Jesse Ausubel, a program officer with the Alfred P. Sloan Foundation, and together they hatched an idea for a program that would become the international Census of Marine Life (CoML) (Ausubel 1999). More on that later.

Working with Judy, we continued to accumulate evidence for habitat selection in settling invertebrate larvae both in flume (Snelgrove et al. 1998) and field experiments (Snelgrove et al. 1999a). Job applications and multiple interviews followed, but the absence of an offer led me to create a collage of rejection letters outside my door, including some I wrote to myself when search chairs did not bother to inform unsuccessful short-listed candidates! I was almost ready to give up, but Judy encouraged patience and kept me trying. A Killam Postdoctoral Fellowship with Jon Grant at Dalhousie brought me back to Canada, and while continuing to build evidence on invertebrate larval habitat selection in natural sediments (Snelgrove et al. 1999b), an offer finally came that would take me right back where I started.

Lesson 6: Persevere with your ideas and keep the passion, noting that someone may respond.

Lessons 7–10—the real world

I arrived at Memorial University in 1996 to take up a faculty position and Industrial Research Chair in Fisheries Conservation. A new book on ecosystem services (Daily 1997) underscored the link between biodiversity and ecosystem services, and Diana Wall (formerly Freckman), a leading soil ecologist (Bardgett 2024), was organizing a series of workshops on biodiversity and ecosystem functioning. She invited Butman, who could not attend but recommended me. A string of syntheses followed on research needs to understand potential links between biodiversity and ecosystem functions such as nutrient cycling, habitat provisioning, and trophic support (Freckman et al. 1997, Snelgrove et al. 1997, Snelgrove 1999, Smith et al. 2000, Snelgrove et al. 2000, Levin et al. 2001). These papers helped spark my own interest and that of the broader research community in biodiversity links to ecosystem functioning, both in terrestrial (e.g. Loreau et al. 2001) and subsequently marine systems (e.g. Solan et al. 2006). These publications would help me gain tenure; however, my new research chair emphasized commercial species, and seafloor ecosystem functioning was not considered a priority. Indeed, I was discouraged from doing such work and advised to focus on local priorities. As someone trained in biological oceanography rather than fisheries, I had to pivot and find a new niche.

As luck would have it, a scientist at Fisheries and Oceans Canada [Department of Fisheries and Oceans (DFO)], Pierre Pepin, had come to my interview seminar on larval invertebrates, and suggested we talk if I got the job. Subsequent conversations with Pepin, who also loaned me equipment and his lab manager to show us the ropes (e.g. Pepin 1991), launched a successful pivot to larval fish ecology. Working with my first graduate student, Ian Bradbury, we produced a series of papers that showed how variation in temperature-dependent development influenced larval dispersal and survival in Atlantic cod, Gadus morhua (Bradbury et al. 2001a, b, 2008) and other species (Bradbury et al. 2003). Others in my lab demonstrated superior swim speeds and greater active habitat selection in demersal versus pelagic spawning fishes (Guan et al. 2008), while another project demonstrated larval supply as a useful predictor of dominant seafloor invertebrates (Quijon and Snelgrove 2005a).

Ilkka Hanski (1999) had recently published his metapopulation biology treatise, and around that time, coral reef fish ecologist Peter Sale organized a workshop on marine population connectivity that fired up the larval ecology community, shifting the emphasis from dispersal to connectivity (e.g. Cowen et al. 2000, Sale 2002). Physical oceanographer Brad de Young and Pepin kindly invited me to join them on a new proposal to use egg production models to estimate population size in groundfish. Although the project yielded better understanding of how to sample fish eggs effectively (Pepin et al. 2005, 2007), understanding connectivity remained elusive, and we began to realize a need to consider ALL life history stages.

Up to that point, our efforts to understand connectivity depended largely on inferences from biophysical modeling. However, Bradbury had moved into a PhD program with Paul Bentzen at Dalhousie and Steve Campana at DFO, and we continued to develop ideas on drivers of connectivity and recruitment variability, adding their expertise on genetics and otolith microchemistry. Focusing on smelt, Osmerus mordax, this work showed that nighttime synchrony in egg hatching, rather than temperature, determines smelt recruitment (Bradbury et al. 2004), and that the interaction between behavior, improved swim speeds with ontogeny, and hydrography enables larval retention in favorable estuarine environments (Bradbury et al. 2006). Drawing on Campana’s expertise, we showed how geochemical signatures in smelt otoliths could link early life history stages to specific habitats, demonstrating the utility of the approach for establishing population connectivity with greater certainty than biophysical modeling (Bradbury et al. 2011). The application of genetics to smelt and white hake, Urophycis tenuis (Bradbury et al. 2009), and cod (Bradbury et al. 2011) demonstrated its utility in elucidating population structure and connectivity.

Lesson 7: The best students teach their mentors at least as much as their mentors teach them.

Bradbury’s new skills in otolith geochemistry and population genetics galvanized a new project that included de Young and juvenile fish specialist Robert (Bob) Gregory to address connectivity in all life history stages of Atlantic cod. Biophysical modeling and sampling of eggs and larvae underscored the importance of coastal circulation in retaining early life stages near appropriate juvenile habitat (Stanley et al. 2012; 2013). Field sampling of otoliths from juvenile cod indicated substantive spatial variation in otolith geochemistry when trying to assign individuals to specific locations (Stanley et al. 2016a), and juveniles reared under different environmental conditions confirmed the need for validation of otolith microchemistry in connectivity studies (Stanley et al. 2015). Behavioral studies showed that juvenile cod nonetheless limit their movement in relation to predation risk (Ryan et al. 2012) and, despite the potential for gene flow, display significant biocomplexity and cryptic diversity (Bradbury et al. 2014).

Although this connectivity work addressed my curiosity on larval ecology, the lack of opportunity to address my interests in biodiversity research and deep-sea ecology in particular left me frustrated and discouraged. Even with the excellent students and some wonderful colleagues, I began to consider a career change, and possibly even leaving science. But then in 2003, another door opened, and I walked through it. Encouragement from de Young, who had been on the search committee that had hired me into the Fisheries Conservation Chair and was part of a search committee for a new Canada Research Chair, led me to apply. I got the position and suddenly had research resources and scope to pursue my own interests. This new position would enable my participation in four major initiatives that would feed my research interests and solidify my enthusiasm for networking.

First, in the late 1990s, John Delaney at the University of Washington floated the idea of a deep-sea cabled observatory in the Eastern Pacific that would span the entire Juan de Fuca tectonic plate (Delaney and Shave 2000). Given its geographic location, the effort would require Canada and the USA to work together, and two initiatives began in Canada, led by the University of Victoria. Responding to a newly created Canada Foundation for Innovation, Chris Barnes launched an effort to fund the Canadian Neptune Observatory (Barnes et al. 2007), and Verena Tunnicliffe began to assemble a team to develop the Venus shallow water observatory, which would serve as a testbed for deeper water as well as a shallow-water observation system (Tunnicliffe et al. 2003). They both kindly invited me to participate in developing the respective proposals, and I eagerly accepted; both projects were funded. That collaboration would enable coastal studies on bioturbation effects on nutrient cycling.

Predator exclusion experiments on the muddy seafloor of hypoxic Saanich Inlet, British Columbia, looked great after the first set of deployments, but repeating the experiment produced ambiguity, and I never published the experiments. However, my initial despair turned around when two postdoctoral researchers working with Tunnicliffe approached me about linking their nutrient flux measurements with my caging experiments to demonstrate the importance of bioturbation on sediment transport (Katz et al. 2012), silica cycling (Katz et al. 2016), and possibly fisheries production (Katz et al. 2009). Although I did not fully realize it at the time, that collaboration would catalyze an expansion of my research from trying to understand drivers of biodiversity patterns to linking biodiversity with ecosystem functioning and services.

The CoML was well underway, funded by the Sloan Foundation, attracting some 2600 scientists from around the world, and Ausubel recognized a need to bring together the 17 major projects within CoML in the last few years of its 10-year cycle (Cressey 2010). In 2007, he invited me to lead a proposal to chair a group to address that need. The Sloan Foundation funded the proposal (the only time in my life I was awarded more than I had requested!). The papers (e.g. Tittensor et al. 2010, Block et al. 2011) and books (McIntyre 2010, Snelgrove 2010) from that synthesis illustrated how to achieve a truly global effort to advance biodiversity, science, and the importance of building relationships and trust.

A third initiative had begun in 2005 on a shuttle ride to the Ottawa airport after a workshop on the future of ocean life when John Roff and Patricia Gallagher suggested I spearhead a Canadian biodiversity conservation initiative. Although the shuttle was delayed and I missed my flight, they had planted a seed; if they felt I could lead a biodiversity initiative, then maybe I could.

At that time, there was no obvious funding pathway, but the following winter, I was in one of the many downtown St. John’s bars discussing ideas for the CoML program with Ausubel and Michael (Mike) Sinclair, Regional Science Director at Bedford Institute of Oceanography (Sinclair sat on CoML’s Scientific Steering Committee). Ausubel envisioned nationally focused biodiversity programs that would complement the international CoML field programs already underway, and Sinclair noted that he could pull together some funds from DFO to catalyze and support a proposal for a Canadian biodiversity program under the CoML umbrella if someone would take that on. I opened my wallet, placed my business card on the bar, and said, “I’m your man, Mike.” A deal was struck.

The Natural Science and Engineering Council of Canada (NSERC), the lead science funding agency for natural science in Canada, had opened a strategic networks funding program and offered supporting funds for proposal development. Combining the funding from DFO with an award from NSERC, I assembled a small team of excellent researchers from academia and DFO (see Snelgrove et al. 2008) to write a large and complex marine biodiversity proposal. In the dead of winter, our team flew back and forth across Canada to pull together ideas solicited from Canadian researchers, often losing a few of us to weather delays, but we got it done. Then in 2008, we launched the NSERC Canadian Healthy Oceans Network (CHONe) (Snelgrove et al. 2008 , Koebberling and Snelgrove 2011), which pulled together some >40 scientists and trained upward of 100 students during its two successful funding cycles spanning 2008–2021.

At this point in my career, I had settled into three interlinked research themes: biodiversity drivers, ecosystem functioning, and population connectivity. Perhaps unsurprisingly, these topics also formed core themes in CHONe. They would also later contribute to a fourth program, the Ocean Frontier Institute, which was funded by a major science funding initiative in Canada called the Canada First Research Excellence Fund, which primarily partnered Dalhousie University and my own institution under the theme of Safe and Sustainable Development of the Ocean Frontier. In 2017, Wendy Watson-Wright, Marlon Lewis, and I worked together to develop the research programs within that initiative, tag-teaming to present the plans and ambitions to a wide range of international partners and developing governance to ensure financial and scientific credibility. Eventually, Anya Waite succeeded Lewis, and we would spearhead a follow-on program called Transforming Climate Action (TCA). Both programs have worked to engage Indigenous communities in developing, deploying, and applying ocean research (e.g. Miatta et al. 2025).

All these programs have trained and helped to place a generation of early-career researchers in a variety of academic and government research positions from coast to coast in Canada and beyond. By networking diverse researchers spanning geographies and disciplines, these programs have advanced scientific knowledge that can inform ocean policy and improve ocean sustainability efforts. Below I summarize some of the research in which I participated to illustrate the immense benefits of networked science.

Lesson 8 – Find true team players and not those who just think they are. Teamwork, teamwork, teamwork can use a diverse toolbox of technologies to solve complex, interdisciplinary challenges and position the next generation of researchers to push scientific achievement further than we can imagine possible today.

Lessons 9–10—applying the tools

 

Biodiversity drivers

My group’s research on biodiversity drivers has focused largely on the role of food quality and supply (e.g. Campanya-Llovet and Snelgrove 2018). Earlier work in coastal Newfoundland showed how snow crab acted as ecosystem engineers (Quijon and Snelgrove 2005b), but having helped to make the Neptune and Venus observatories a reality, I wanted to use them. As largely fixed assets spatially, observatories provide excellent temporal data, but seafloor ecology typically focuses more on spatial dynamics, requiring ship-based sampling often augmented by detailed temporal observations. Work in Barkley Canyon off the British Columbia coast demonstrated the important role of food sources in determining deep-sea macrofaunal composition and diversity (Campanyà-Llovet and Snelgrove 2018a,b, 2019). On Canada’s East Coast, in addition to demonstrating the role of food supply for seafloor diversity (Miatta and Snelgrove 2021), video surveys showed how some demersal fishes associate with deep-water corals (Baker et al. 2012), that distinct macrofaunal communities live near deep-water sea pens (Miatta and Snelgrove 2022), and that geological topography drives continental slope macrofaunal (Ciraolo and Snelgrove 2023) and microbial (Ciraolo et al. 2023) patterns. Shallow-water baited camera work in coastal Labrador demonstrated the importance of habitat differences to relative abundances of demersal fish communities (King et al. 2025). Collectively, this work has demonstrated the strong interplay between environment and biology in setting biodiversity patterns in marine seafloor environments.

Ecosystem functioning

Beyond habitat provisioning, much of our work on ecosystem functioning has focused on the role of sedimentary fauna in nutrient cycling. Using the environmental data stream available through Ocean Networks Canada in shallow waters of Saanich Inlet and Strait of Georgia, British Columbia, Belley and Snelgrove (2016) determined that environmental variables (bottom water oxygen concentrations and temperature, sediment grain size/organic content) and functional diversity of macrofauna contributed about equally in explaining ∼2/3 of the variation in benthic nutrient fluxes. Based on phytoplankton enrichments of experimental cores, Belley and Snelgrove (2017) attributed greater benthic flux rates in Strait of Georgia sediments to higher species richness and especially higher densities of detritivores and omnivores. Sampling continental slope sediments off eastern North America showed that biological and environmental variables did not predict variation in nutrient flux rates (Ciraolo et al. 2023), whereas using cameras and acoustic data from NEPTUNE, we inferred that more intense sediment reworking coincided with the highest oxygen concentrations in bottom water (Ciraolo et al. 2024). This body of work has led us to emphasize the utility of train analysis in biodiversity-ecsystem functioning studies (Miatta et al. 2021).

Connectivity

The studies above that describe habitat provisioning as a driver of biodiversity patterns also straddle the theme of connectivity, where continuing work in shallow coastal waters with Bob Gregory and our students builds on previous work (e.g. Warren et al. 2010) showing that juvenile cod use eelgrass habitat as a predator refuge; our recent work shows limited winter movement (Geissinger et al. 2022), but greater summer juvenile movement than previously thought (Shapiera et al. 2014). Analysis of a long-term data set showed the utility of using juvenile cod abundance as a predictor of recruitment over continental shelf spatial scales Lunzmann-Cooke et al. (2021). Acoustic tagging of golden cod, a unique subspecies, showed that seasonal movement of adults outside the perimeter of the marine protected area created to protect them likely contributed to their continuing decline (Morris et al. 2014). Several recent studies drawing on genetic tools in the context of metapopulations show population-level differences in adaptations in Atlantic cod (Bradbury et al. 2014) and in Arctic charr (Layton et al. 2020, 2021) related to their capacity to respond to climate change.

Genetics also helped in identifying a genetic discontinuity in scallop populations (Placoplecten magellanicus) on the east coast of North America (Wyngaarden et al. 2017), which we would soon find aligned closely with five other species with variable life history strategies (Stanley et al. 2018). In all cases, ocean temperatures explained the discontinuity, and that knowledge would inform management of all the study species. Flume experiments demonstrated that postlarvae of American lobster (Homarus americanus) in flow were less likely to dive and search the bottom for suitable habitat than in still water, suggesting that bottom flow influences encounter rates with the seafloor (Lillis and Snelgrove 2010). Laboratory experiments on larval American lobster identified how developmental stage, temperature, and natal origin add potentially important sources of variability in behavior, whose consideration could improve the utility of biophysical modeling (Stanley et al. 2016b, Pedersen et al. 2017). Biophysical modeling of northern shrimp (Pandalus borealis) that considered different release locations and behaviors for larval stages identified important source and sink locations for populations off Newfoundland and Labrador (Le Corré et al. 2019, 2020).

This body of work collectively illustrates contrasting roles and scales of effect for different life history stages within and between fishes and benthic invertebrates (Bradbury and Snelgrove 2001a, Bradbury et al. 2008), where larval stages contribute greatly to connectivity in both groups, juvenile stages appear to play a very modest role for both groups, and adults play a much more substantive role in many fishes than in benthic invertebrates. Importantly, advances in biophysical modeling, otolith microchemistry, and genetics in particular have greatly expanded our knowledge of connectivity in marine biota, opening up new opportunities for improved ocean use management and sustainability of biodiversity.

Lesson 9 – While we will probably never manage the global ocean, we can certainly manage ocean use more effectively today than we could even a few decades ago. New discoveries relating to biodiversity prediction, ecosystem functioning, and population connectivity enable improved science advice, which can inform better policy decisions.

The value of synthesis

CoML taught me the value of synthesis and communication, but it also catalyzed many collaborations and friendships, one formed with Roberto Danovaro, who invited me to visit him in Italy and write about emerging deep-sea research priorities (Danovaro et al. 2014, 2017a) and infrastructure needs (Danovaro et al. 2017b, 2020) in light of global change. That collaboration continued with a new marine biology textbook that saved our sanity during the COVID-19 lockdown (Danovaro and Snelgrove 2024). These types of syntheses, which provide a form of “one-stop shopping” for those less interested in the technical details of individual studies, can provide high-level perspectives on topics that can inform sustainable ocean efforts, ranging from baseline biodiversity knowledge (Archambault et al. 2010, Wei et al. 2020) and transferability of models (Yates et al. 2018) to meeting biodiversity goals (Diaz et al. 2020) and ecosystem-based management approaches (Dickey-Collas et al. 2022).

Looking forward—marine conservation and sustainable oceans

Past and present changes in the global ocean will continue in the future, but we now have pathways to plan for it. Habitat suitability models indicate potential climate refuges for deep-water corals (Morato et al. 2020) and shifts and overall habitat loss for key North Atlantic commercial species (Stanley et al. 2018). We anticipate that warming may fundamentally alter sedimentary nutrient cycling (Bianchi et al. 2021) and that climate change effects and other human disturbances will likely permeate even the most remote deep-sea environments (Levin et al. 2020). We can plan for such change, particularly given that the science community has identified key variables for monitoring change (Woodall et al. 2018, Danovaro et al. 2020) as well as priority data gaps (Howell et al. 2021). Coupled climate and biological modeling approaches can help in predicting the most vulnerable locations and identifying those that may be most valuable in sustaining biodiversity and functioning (Levin et al. 2020). The new Biodiversity Beyond National Jurisdiction (BBNJ) agreement offers hope for deep-sea conservation, as well as capacity building and stronger scientific collaboration (Harden-Davies and Snelgrove 2020), including engagement with and incorporation of Indigenous knowledge (Miatta et al. 2025).

Translation of science advice to policy requires communication beyond primary journal articles and knowing how to reach a target audience. In 2020, just prior to the COVID-19 lockdown, I accepted a secondment to work with Fisheries and Oceans Canada as Departmental Science Advisor, which provided an interface between Canada’s Chief Science Advisor, Mona Nemer, and the science-based federal departments. Working closely with the Assistant Deputy Minister of Science, Arran MacPherson, I have learned how science advice works and the intricacies and challenges of providing effective, objective science to support evidence-based decisions. The current strong emphasis in Canada on open science, including the data and basis for science advice, stands in stark contrast to some other nations that eschew open, evidence-based science.

Lesson 10: We can and must do better on sustainable ocean efforts, and we have the tools and opportunities to do so. Mustering the societal will hinge on communicating the challenges and needs for a healthy and sustainable ocean.

Acknowledgments

I thank the many students and postdocs who made up the collective engine that drove the research ship described here. Honors students include Devon Bath, Chelsea Bloom, Kate Gardiner, and Margaret Warren. Graduate students include Krista Baker, Renald Belley, Ian Bradbury, Victoria Burdett-Coutts, Neus Campanyà y Llovet, Kelly Carter, Alessia Ciraolo, Mary Clinton, Ty Colvin, Emilie Geissinger, Lu Guan, Michael Kelly, Ben King, Ashlee Lillis, Emma Lunzmann-Cooke, Marta Miatta, Corey Morris, Pedro Quijon, Harshana Rajakaruna, Patricia Ramey, Melanie Rossong, Mary Ryan, Dustin Schornagel, Melanie Shapiera, Ryan Stanley, and Mallory Van Wyngaarden. Postdoctoral researchers included Richard Allen, Ian Bradbury, Neus Campanyà y Llovet, Alexandra Curtis, Nicolas LeCorre, Kara Layton, Marta Miatta, Barbara Neves, Ryan Stanley, and Chih-Lin Wei. Much valued collaborators include Chris Algar, Phillipe Archambault, Krista Baker, Amanda Bates, Ian Bradbury, David Cote, Roberto Danovaro, Brad de Young, Bob Gregory, the late Kim Juniper, Peter Lawton, Lisa Levin, Anna Metaxas, Corey Morris, Barbara Neves, Alf Norkko, Chris Parrish, Pierre Pepin, Simon Thrush, Verena Tunnicliffe, and Sue Ziegler. Lab assistants who have helped with his work include Vanessa Byrne, Sandy Fraser, Silas Jones, Vanessa Reid, and Christine Vickers. The Natural Sciences and Engineering Research Council of Canada (NSERC) has funded much of the research described here, with additional support from Fisheries and Oceans Canada. I thank Ian Bradbury, Michele DuRand, Judy Grassle, two anonymous reviewers, and Howard Browman for their helpful comments on an earlier draft of this essay. Finally, I thank Simonetta Fraschetti and the 2024 European Marine Biology Symposium for their invitation to Naples as a plenary speaker; that invitation, and Howard’s encouragement, catalyzed this enjoyable look back in awe.

Author contributions

Paul Snelgrove (Conceptualization, Funding acquisition, Writing—original draft, Writing—review & editing).

Conflict of interest

None.

Data availability

This synthesis generated no new data or analyses.

Notes

Food for Thought articles are essays in which the author provides their perspective on a research area, topic, or issue. They are intended to provide contributors with a forum through which to air their own views and experiences, with few of the constraints that govern standard research articles. This Food for Thought article is one in a series solicited from leading figures in the fisheries and aquatic sciences community. The objective is to offer lessons and insights from their careers in an accessible and pedagogical form from which the community, and particularly early career scientists, will benefit. The International Council for the Exploration of the Sea (ICES) and Oxford University Press are pleased to be able to waive the article processing charge for these Food for Thought articles.

References