Unfolding the Earth

I'm currently taking an introductory class on working with spatial data using ArcGIS. We've been discussing the use of different coordinate systems and their components this week, including the various projections used in projection coordinate systems.

This is a video of some of the many ways you can unfold the Earth into a flat map...

Sea lion vs. camera

Digging into the backlog of things I've meant to post, here is an excerpt of one of the videos from the fish diversity recordings featuring a curious sea lion trying to eat the camera...




As it swims off it goes right for the transect tape, which is why you see the tape move up into the camera frame. We've seen this kind of demonic intrusion before...

The camera sees all: Manta ray at Baltra

Over a week after one of our early dives at Isla Baltra, I review the video from the GoPro recordings and see this. None of us knew it, but we were diving with a manta ray. I guess we should look up from working on the bottom once in a while... :)

Does fish diversity matter?

Previous work out of the Witman lab has looked at how sea urchin diversity affects processes like grazing rates in the Galapagos. Now the focus is shifting higher up the food chain to the things that eat sea urchins. More specifically, does the diversity of urchin predators affect the intensity of predation on urchins? Are there interactions between the different urchin predators that may alter predation rates? My own project aims to figure out to what extent seastars such as Pentaceraster are a part of this predation. The other obvious suspects would be predatory fishes.

Whodunit.

To get some preliminary data on the diversity of fishes (with a special interest in species that could potentially eat urchins), we've been deploying a bunch of Hero GoPro cameras at multiple sites around the central Galapagos archipelago to record 3-4 hours of continuous video data on the fish that are present. These little wearable cameras were originally made for filming high-definition extreme sports videos, but work extremely well as our underwater data-collectors - we've made little stands for them that weight them down on the rock (usually we also stick a few rocks on the stand for greater stability).

Deploying the camera system

GoPro in its natural habitat

During our 5-day research cruise, we collected fish diversity data from 11 different sites, deploying 2 cameras per site for a minimum of 1 hour continuous video data per camera. Video data are easy to collect and accumulates quickly, but it will probably take many more hours in the fall and spring to analyse fish diversity from the raw data.

Here is a one of the more exciting excerpts from Rocas Cousins, a site on the north side of Santa Cruz. How many fish species can you spot? (If you're not too distracted by the charismatic trio of ray, sealion and turtle...)