Cool Papers 3: Citizen Scientists to the rescue!

By Danielle Ludeman

Let’s face it – the world we are leaving for our children is not going to be the same one we grew up in.  But although biodiversity is being lost in our ecosystems at an accelerating rate, around the world there are countless tales of people doing their part in trying to preserve, conserve, and manage our natural resources.  Before we can protect biodiversity in ecosystems we need to know what there is to protect, and an important challenge for ecologists is to determine geographical patterns in biodiversity, which requires extensive data collection. More and more we are relying on ‘citizen’ scientists to help in this key step, and hundreds of thousands of volunteers each year take part in a variety of surveys, bioblitzes, and monitoring programs.  But how reliable can the data be?

In a paper that came out last week in “Methods in Ecology and Evolution”, researchers Dr. Ben Holt and colleagues have shown that Citizen Science can be just as effective in recording marine biodiversity as traditional scientific surveys. The study compared two methods of acquiring biodiversity data: a belt transect typical in peer-reviewed scientific articles, and the ‘roving diver technique’ used by the REEF (Reef Environmental Education Foundation) program.  Volunteers, no matter how enthusiastic they are, typically don’t have the training to use traditional scientific protocols, therefore most Citizen Science programs use alternate methods and techniques that may affect the outcome of the biodiversity survey.  This study therefore set out to try to determine how much the two methods differed when assessing the biodiversity in the Turks and Caicos Islands. They found that the two methods were consistent in their diversity estimates, with REEF’s rover method actually finding significantly more species than the belt method.  This rover method was not always the best method to use, as belt transects were more suitable for species richness estimates. However, the vast quantity of data that can be collected using REEF’s rover method and the consistency to diversity estimates of more traditional methods suggests that Citizen Science programs such as REEF can be invaluable for large-scale biodiversity surveys.

Divers performing a belt transect survey as part of a Citizen Science program called ReefCheck in Honduras.  Credit: D Ludeman

Divers performing a belt transect survey as part of a Citizen Science program called ReefCheck in Honduras. Credit: D Ludeman

Citizen Science is happening all around us. The REEF program has collected over six million sightings across 10 000 locations.  Audubon’s Christmas Bird Count has finished its 113th year, with tens of thousands of participants collecting data from over 2000 circles.  Government programs such as British Columbia’s ‘Report-a-Weed’ helps in early detection and rapid response to invasive species.  And programs such as the Canadian Wildlife Federation’s Bioblitz gets families from across Canada learning the plants and animals found in their own backyard.

So how about lets all get there and do our part!  Here is a (brief) list of just some of the Citizen Science programs that are happening out there.  Feel free to add more in the comments section, or send us a message at to get us to add yours!

REEF (Reef Environmental Education Foundation)
Audubon’s Christmas Bird Count
British Columbia Breeding Bird Atlas
Whistler Biodiversity project
E-flora BC
Alberta Mycological Society
Alberta Plantwatch
Project Noah
Monarch Larva Monitoring Project

Cool Papers! Part 2: Hermit crabs with a not-so ‘hermit’ lifestyle

By Danielle Ludeman

‘Hermit’ crabs seemingly implies that they are just that – hermits – living alone in their own (second-hand) shell, apart from society (i.e. their kin).  But are they as alone as their name implies?

According to a new study by Mark Laidre, terrestrial hermit crabs are forced to socialize if they want to find a new shell to move into! Carrying around giant shells on land would be heavy, and so terrestrial hermits, unlike marine hermit crabs, modify their gastropod shells by eroding the interior and creating a larger and more lightweight home. This also takes time, and so hermits will move into previously modified shells, if they are available, when it is time to move into a larger one.  To look at the consequences of this modification, Mark Laidre placed hermits in either 1) new unmodified shells or 2) previously remodeled shells of the same diameter, and found that only the hermits in the shells passed down from other hermits survived! The hermits in the unmodified shells could not fit into the small amount of space available, and thus they did not have full protection against ant attacks. There are virtually no unoccupied remodeled shells in the population, so when it comes time to moving on up into a bigger shell the hermits benefit from being around others if they want any hope in finding a previously remodeled shell!

Laidre calls this remodeling of the shell ‘niche construction’ (the process in which an organism changes its environment).  According to the fossil record, this ‘niche construction’ has been taking place in terrestrial hermit crabs for millions of years! Laidre argues that that is ample amounts of time for such a trait to start to drive social behavior, so that these remodeled shells become a form of ‘ecological inheritance’, where modification of the environment is reused by many successive generations.  Unlike genetic inheritance, ecological inheritance can be passed on to individuals that are unrelated.  These remodeled shells, therefore,may be a driving force for social dependence, even among unrelated individuals.

As it turns out, the need to find a new shell when a hermit crab grows drives another form of social behavior as well!  When a new shell becomes available in the environment, many hermit crabs gather round forming something called a ‘vacancy chain’. The hermit crabs will essentially line up from biggest to smallest (albeit in a not-quite so elegant fashion), taking the next biggest shell as it becomes vacant!

Cool Papers! Part 1: An appetite for glass

By Danielle Ludeman

As scientists, we all have to keep up to date on the happenings in our field.  Although reading papers is not usually my favorite part of doing research, I love that moment when I stumble across a really cool paper and immediately want to run and share my find with someone.  Whether you react that way or not, cool papers help to remind us of why we do what we do, and motivate us to keep plugging away at our own research, because we just might get a cool paper out of it too.  So to share some of the cool papers in marine science that are out there, I am going to post them to this blog.  And what better way to start off the cool papers section than to post about a paper from the Bamfield Marine Science Station’s very own Jackson Chu (and former member of the Leys lab) and his recent paper on predators of glass sponge reefs published in Invertebrate Biology.  Now I may be a little biased in thinking this paper is really cool because it’s about sponges.  And I was part of the 2009 research cruise when the first nudibranchs on the glass sponges were found.  But seriously – glass-eating nudibranchs?! Super cool.

Alright let’s back up a second here – glass sponge reefs?  Yup, glass sponges (Class Hexactinellida) in the deep, deep waters off of British Columbia form huge reefs, much the same way that corals form reefs in tropical waters!  These vast and majestic glass sponge reefs span hundreds of kilometers along the coast – one of them even lies just at the doorstep to Vancouver, at the base of the Fraser River.  Yet even though they live just below our feet, their deep-water habitat of about 100-200m deep meant that we only discovered them about 25 years ago, and we still have much to learn about this important ecosystem!

Glass sponge reef in the Strait of Georgia, viewed from ROPOS. Photo credit: A Kahn

Glass sponges are made out of just that – glass.  They form a silica-based skeleton that comprises >90% of their body weight, leaving less than 10% to organic living tissue. Because of this, very few animals are expected to feed on them.  But in 2009 and 2011, while surveying the reefs aboard a research vessel equipped with the remotely operated vehicle ROPOS, Chu and Leys noticed two species of large dorid nudibranchs, Peltodoris lentiginosa and Archidoris odhneri, sitting on top of some of the glass sponges on two of the three reefs visited.  Now because nudibranchs are notorious sponge-eaters, they had a hunch that these cute little guys may actually be voracious predators in disguise.

Glass sponge-eating dorid nudibranchs found during the 2009 cruise of the Strait of Georgia glass sponge reefs. Photo credit: D Ludeman

So how do you know the nudibranchs are actually eating the sponges? By looking inside their stomachs!  By doing so, Jackson found that their stomach and fecal contents were full of spicules unique to both of the main reef-forming species of glass sponges, making these two species of dorid nudibranchs the first known predators of BC’s glass sponge reefs.  And the small amount of organic tissue compared to glass in the sponges must mean the nudibranchs have to eat A LOT of glass to sustain their large size! Nom nom nom.