New publication on larval corals and their algal symbionts

An exciting collaboration ended with coral babies making a journal cover (we’re honored)! This amazing photo, taken by Marhaver lab members at CARMABI Curaçao, shows baby star corals just after they have gone through metamorphosis. In this species, parents do not provide offspring with the algal symbionts they need to survive as adults. Instead, these baby corals must find them in their environment—or in the lab, as it may be. You can see the algal symbionts in the photo below as the tiny brown dots within the newly settled corals.

Paper summary: Even though it may seem like the sooner larvae can take up symbionts the better, we found that when swimming larvae take up symbionts it can actually throw off some of their behaviors and alter the ways they express genes and use energy (akin to the yolk). We concluded that these responses to taking up symbionts “early” is not beneficial to the larvae despite the fact that they benefit a great deal from these very same symbionts later in life. This means that while larvae can and will take up symbionts if they’re readily available, those that wait until later in life may survive better in the long run.

The citation is below and a pdf can be downloaded here.

A.C. Hartmann, K. L. Marhaver, A. Klueter, M. Lovci, C. J. Closek, E. Diaz, V. F. Chamberland, F. I. Archer, D. D. Deheyn, M. J. A. Vermeij, M. Medina (2019)Acquisition of obligate mutualist symbionts during the larval stage is not beneficial for a coral host. Molecular Ecology, 28, 141-155.


Small molecule diversity on coral reefs at the World Conference on Marine Biodiversity (Montreal)

Animals produce certain molecules (think venoms) in order to fight for resources like space and food. In one of my projects, I am studying the mostly-unexplored diversity of molecules in coral reef organisms throughout the Coral Triangle, the most species-diverse spot in the ocean and maybe even the planet.


I’m trying to answer questions such as: Is small molecule diversity determined by the extent to which species are related? Or, is small molecule diversity determined by local communities and conditions? (local, it seems so far). I’m also interested in how much small molecule diversity is left to discover (lots and lots!). Quantifying this potential helps us understand why organisms win or lose on the reef and tells us that coral reef molecules have vast potential to benefit of humans (such as new medicines).


In May I gave talked about our preliminary findings at the World Conference on Marine Biodiversity in Montreal. I’m running follow-up analyses and will have more findings to share soon.

In the image below, all the grey circles are molecules found widely in the Coral Triangle, while the colored molecules are only found in one region. A molecular family is a group of molecules with similar structures and a modification relates to the chemistry that turns one molecule into another. You can read our paper on how we find modifications here.

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Conservation Biology class field trip to Maine, March 2018

Over an action-packed two days, my Harvard University Conservation Biology students visited five organizations to learn about marine conservation efforts in Maine. In particular, we got a close look at the interface between marine sustainability and aquaculture. Our stops included the Gulf of Maine Research Institute, Mook Sea Farm, Bigelow Marine Labs (including a delicious seaweed-focused dinner by Ocean's Balance), the Ocean Approved seaweed farm, Bangs Island Mussels, and the Friends of Casco Bay


Getting a tour from Bill Mook at Mook Sea Farm, an oyster producer and one of the largest oyster seed hatcheries on the US east coast.


Checking out the Bangs Island floating mussel farm with Paul Dobbins of Ocean Approved seaweed.


Talking seaweed farming and getting out on Casco Bay with Paul Dobbins of Ocean Approved seaweed farm.

Careers in Conservation workshop at Harvard, February 2018

Interest in careers in environmental conservation is thriving at Harvard University and is led by the Harvard College Conservation Society. Every year the society organizes a Careers in Conservation Conference and I was honored to lead a workshop about career paths and work in the field of conservation biology. The free event is held every February and I strongly encourage anyone with interest in the field to attend.