Methods for Ocean Conservation: World Ocean’s Day 2020

Post provided by Chloe Robinson


Whether you refer to them as the ‘briny deep’, the ‘seven seas’ or ‘Davy Jones’ locker’, the world’s oceans play a huge part in all of our lives. Consisting of 70% of the earth’s surface, oceans driving global weather patterns, through regulating a conveyor belt of heat from the equator to the poles. Oceans are also teeming with life, from single-celled organisms to large apex predators, such as the killer whale (Orcinus orca).

Male killer whale exhaling. Photo credit: Chloe Robinson/Sea Watch Foundation.

As with every other ecosystem on earth, the world’s oceans and the marine life they provide a home to, are under increasing pressure from human-related activities. At the 1992 Earth Summit, Canada proposed the concept of a World Ocean Day as a day to celebrate our oceans and to raise awareness about the crucial role the ocean plays in our lives and the important ways people can help protect it. Since 2002, the Ocean Project has been coordinating and promoting of World Ocean Day.

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Using Shark Scales to Unlock the Secrets of Historical Shark Communities on Coral Reefs

Post provided by Erin Dillon

Close your eyes for a second and imagine a coral reef. What do you think the shark community on that reef looked like historically?

Grey reef sharks on Palmyra Atoll’s forereef. ©Darcy Bradley.

Perhaps you imagined a remote reef with high shark abundance like Fakarava, French Polynesia or Palmyra Atoll, Northern Line Islands. Maybe you thought of a marine protected area such as Jardines de la Reina National Park in Cuba. Or perhaps you relied on your own memories from snorkeling on reefs in the past or photos of reefs taken decades ago.

The answer to this question depends on a reef’s location, given that shark abundances can vary with primary productivity and other oceanographic features. It also depends on which time period you chose as your reference point. Shark abundances can fluctuate over the course of a few hours – as well as over days to years to decades and beyond. Even if you chose the same time and place as the person before you, you might have come up with a slightly different answer. This variation in how we determine baselines – overlaid on a backdrop of natural variation in shark communities over space and time – can contribute to differing perceptions about what’s natural or what a depleted population can possibly be restored to.

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Using Molecular Power to Reconstruct Hyperdiverse Food Webs

Post provided by JORDAN CASEY

Coral Reefs: The Ocean’s Most Extravagant Buffet

Coral reefs are home to an incredibly diverse array of species ©Jordan Casey

Coral reefs are home to an incredibly diverse array of species ©Jordan Casey

There are an estimated 830,000 species on coral reefs worldwide. At some stage in their lives, nearly all of these species are consumed as prey items. In this super diverse buffet of fishes, corals, crabs, worms, and other critters, the number of possible interactions between predators and prey is nearly inexhaustible.

The extreme diversity of coral reefs has fascinated naturalists for centuries. Pinpointing predator-prey dynamics is essential to fully understand coral reef ecosystem dynamics, and visual analysis of gut contents has been a staple technique of coral reef ecologists. While the joy of spending copious hours looking through a microscope at half-digested marine mush is undeniable, this type of visual inspection has limitations. Even so, visual gut content analysis (along with stable isotope analysis and behavioural observations) has showcased a highly complex dietary network.

To digest this extreme complexity and surmount the hurdle of dietary unknowns, researchers frequently lump fishes into broad trophic categories, such as ‘mobile herbivores’. Broad generalisations are pragmatic and may be help us detect broad ecological trends, but they oversimplify species’ actual dietary preferences. As coral reefs are changing due to anthropogenic disturbances, it’s critical to thoroughly examine how well trophic groupings capture dietary linkages among reef organisms. Continue reading

Issue 10.5: Movement Ecology, Palaeobiology, Monitoring and More

The May issue of Methods is now online!

The May issue of Methods in Ecology and Evolution is absolutely packed! We’ve got a new ecoacoustics method from Metcalf et al. and a new inference and forecasting method from Cenci et al. There’s also a forum article on image analysis, and papers on physiology, palaeobiology, capture-recapture and much more. We’ve got SIX papers that are freely available to absolutely everyone this month too.

Find out a little more about the new issue of Methods in Ecology and Evolution (including details about what the diver is doing to the coral in the cover image) below. Continue reading

Bottom-up Citizen Science and Biodiversity Statistics

Post provided by Ditch Townsend and Robert Colwell

Different Paths to Science

Ditch Townsend on Exmoor in Devon, UK

Ditch Townsend on Exmoor in Devon, UK

DITCH: Amateur naturalists from the UK have a distinguished pedigree, from Henry Walter Bates and Marianne North, to Alfred Russel Wallace and Mary Anning. But arguably, the rise of post-war academia in the fifties displaced them from mainstream scientific discourse and discovery. Recently, there has been a resurgence of the ‘citizen scientist’, like me, in the UK and elsewhere – although the term may refer to more than one kind of beast.

To me, the ‘citizen scientist’ label feels a little patronising – conveying an image of people co-opted en masse for top-down, scientist-led, large-scale biological surveys. That said, scientist-led surveys can offer valid contributions to conservation and the documentation of the effects of climate change (among other objectives). They also engage the public (not least children) in science, although volunteers usually have an interest in natural history and science already. For me though, the real excitement comes in following a bottom-up path: making my own discoveries and approaching scientists for assistance with my projects.

Robert Colwell at the Boreas Pass in Colorado, USA

Robert Colwell at the Boreas Pass in Colorado, USA

ROB: I grew up on a working ranch in the Colorado mountains, surrounded on three sides by National Forest and a National Wilderness Area. My mother, an ardent amateur naturalist, taught me and my sister the local native flora and fauna and our father instilled a respect for the land in us. For my doctoral research at the University of Michigan, I studied insect biodiversity in Colorado and Costa Rica at several elevations. The challenges of estimating the number of species (species richness) and understanding why some places are species-rich and others species-poor has fascinated me ever since. Continue reading

Progressive Change BACIPS: Estimating the Effects of Environmental Impacts over Time

Post provided by Lauric Thiault

BACIPS (Before-After Control-Impact Paired Series) is probably the best-known and most powerful approach to detect and quantify human interventions on ecosystems. In BACIPS designs, Impact and Control sites are sampled simultaneously (or nearly so) multiple times Before and After an intervention. For each sampling survey conducted Before or After, the difference in the sampled response variable (e.g. density) is calculated. Before and After differences are then compared to provide a measure of the effect of the intervention, assuming that the magnitude of the induced change is constant through time. However, many interventions may not cause immediate, constant changes to a system.

We developed a new statistical approach – called Progressive-Change BACIPS (Before-After Control-Impact Paired-Series) – that extends and generalises the scope of BACIPS analyses to time-dependent effects. After quantifying the statistical power and accuracy of the method with simulated data sets, we used marine and terrestrial case studies to illustrate and validate their approach. We found that the Progressive-Change BACIPS works pretty well to estimate the effects of environmental impacts and the time-scales over which they operate.

The following images show the diversity of contexts in which this approach can be undertaken.

To find out more about Progressive Change BACIPS, read our Methods in Ecology and Evolution article ‘Progressive-Change BACIPS: a flexible approach for environmental impact assessment’.