Manta Rays, Monk Seal, and Pearl Oyster - Yay!!

Since Don arrived on Thursday, I’ve kept him very busy doing lots of forereef dives for my bivalve surveys (8 so far in 3 days).  Forereef dives are always exciting because they’re deeper, with potentially stronger currents and waves, and unprotected by the atoll rim.  Plus, they look very different and have different fishes, corals, and other organisms.  There are also a lot more bivalves than we see inside the reef!

While diving, we’ve observed lots of bivalves, nudibranches, crown-of-thorns sea stars (which, in large numbers, cause problems in other places, but haven’t caused a problem yet in the Northwestern Hawaiian Islands), sharks, giant trevallies (uluas), Potter’s angelfishes, Hawaiian morwongs, and much more.   Here's Don collecting a sediment sample behind an endemic (and relatively rare) Hawaiian morwong.

While outside the reef on the boat, we watched 2 big manta rays just outside the channel and several brown boobies sitting on the reef or on buoys.  The manta rays were particularly cool because we don’t see them very often and these stayed on the surface close to us long enough to get good photos!

I let Don take a land day on Sunday while I took the new FWS volunteers Dani, Eamon, and Anthony out to collect coral reproductive samples.  It’s a good project to take others out for, because they get to see at least three totally different habitats and they can just snorkel around for fun while I work.  They were very excited when a monk seal followed us around for a while and we saw a shark. 

I was very excited that they helped me find the first live adult pearl oyster I’ve seen for most of the summer!!

While Don and I have been diving, Anne’s been finishing measuring the piers and analyzing that data, preparing and testing our underwater video camera, and much more.


I posted a lot more photos today at http://picasaweb.google.com/MidwayCoralReef/2011.

Gasping for Breath . . .

In our last few days before our advisor Don Potts arrives, we've been trying to get everything done that we possibly can free-diving and snorkeling, so we can maximize our scuba diving time when I finally have a dive buddy.  So I've been free-diving for bivalve surveys to 10 ft, which is okay if the habitat is just sand, but much harder when I have to turn over lots of pieces of rubble to look for bivalves.  Free-diving so much, even to a shallow depth, is exhausting!  Ray helped me do that on Saturday and I was very excited to find one pearl oyster on a piece of rubble.  We also saw a shark, a big orange hermit crab, and a few collector urchins.  Ray and I also retrieved a large net, one of several I've helped remove this summer.

Here's me searching for bivalves in a rubble/sand habitat and the one pearl oyster I found there.

I also had to free-dive to check my tiles, which was not the plan since they're at 7-15 ft deep.  However it worked, at least until this turtle suddenly appeared right in front of me and scared the hell out of me just after I'd seen a shark!  He circled around me several times, so I have lots of great photos of him!

I also checked my spat collectors for bivalve recruitment (or rather I retrieved them and Anne checked through them while I checked my tiles in the water).  They're singularly uninteresting right now because we moved nearly all of the pearl oysters to tiles and we're receiving very little recruitment so far this year.  I even looked for two pearl oysters that Don and our field assistant Kate had found in the harbor two years ago, but found no pearl oysters - there was some cool calcified green algae Halimeda and lots of juvenile fish and Spondylus cliff oysters though.  

The last two days, despite beautiful weather, we've stayed on land because we don't have much more work to do on the water without being able to scuba dive.  We've done paperwork, mailed off a sample of pressed algae from the bloom we saw last week, and power-washed the boat today, which was exhausting and very, very hot in the sun!!

We're looking forward to having Don here tomorrow because we can scuba dive and we'll have someone new to work with!  However, we'll miss lots of people leaving tomorrow, including FWS permit coordinator Ray Born who came out on the boat with me several times, Leanne Woodward who was here to facilitate a study of how the tsunami affected the Bulky Waste Dump on the south side of the island but tells hilarious stories at meals, and refuge biologist Pete Leary who's going on vacation but won't be back before we leave.

Turtles & Algae Blooms

Lots of rainy weather has been keeping us from getting much done, but we've worked on the reef a few days and seen some interesting things!
The NOAA ship Oscar Elton Sette came by for a few hours on 8/12 to drop off several invasive plant, monk seal, and turtle researchers from French Frigate Shoals and Kure.  I was impressed to learn that the turtle researchers observed over 800 nesting green turtles this year, which is a record!  They were here for several days before the next plane on 8/18, so they volunteered with FWS and were a great infusion of young (mostly female) people to the island!

The albatross fledglings are almost gone - I think I've only seen a couple in the last few days, so the island's pretty empty during the day.  However, at sunset, thousands of Bonin petrels fly in to rest in their burrows.  They're very disoriented by light, so they make walking, biking, and driving at night dangerous and often fly into lit windows.  

In the few days we've been able to work on the reef in the last week or so, we've observed the first confirmed observation of a hawksbill sea turtle in many years (we're not sure when the last one was!) and documented a small algae bloom.  Since the first monotypic (1 species) algae bloom documented at Midway was in 2008 (my first scientific publication in a journal!), this is very interesting and we'll be watching it closely.  It's particularly interesting because this seems to be a different species that is known for being invasive, although it is native, and smothering coral and other algae in seasonal blooms off Maui.

Cages!

Well, you may have noticed that I have the opposite problem this week.  So much has been happening that I haven’t had time to post a blog entry for 10 days! 

First, since Anne’s been feeling better, we spent the last week drilling holes and installing cages for my pearl oyster survival, growth, and predation experiment.  We’re almost done and will deploy the actual pearl oysters today.  It wasn’t super exciting, but we did see a shark and a turtle while we were doing it.  We’re very excited to finally start the experiment!!!

Second, the Hi’ialakai was here Friday to Sunday, which made for some fun evenings including a bonfire their final night.  They had 50 crew members and scientists who were working on coral reef research of a variety of types – coral & fish disease, acoustic (sound) monitoring, etc. 

Sunday, Pete the refuge biologist offered to drive the boat for a fun snorkeling trip.  We ended up heading to our coring and reef growth location on the SE side of the atoll, which hosts a great diversity of corals and fishes as well as high coral cover.  Pete was very impressed, took lots of photos, and wanted the GPS point in order to return!  He posted several amazing photos from our snorkel trip on his blog on Sunday: http://peteatmidway.blogspot.com.   I was able to check our coring sites on the reef crest and make sure that our concrete fill worked.  Construction worker Derek and I also picked up several small marine debris nets.

Also, here's an interesting article from the National Wildlife Federation on what it was like to experience the tsunami and its aftermath at Midway: http://www.nwf.org/news-and-magazines/national-wildlife/birds/archives/2011/seabird-rescue-midway.aspx