Phoenix Islands Blog

Showing posts with label MOCNESS. Show all posts

7/25/14

SEA 2014: The birds at Birnie (July 25)

A six-week expedition with Sea Education Association (SEA) to the Phoenix Islands Protected Area (PIPA) is underway. This will mark the first-ever oceanographic cruise to PIPA, and is a historic collaboration between SEA, the New England Aquarium, Woods Hole Oceanographic Institution and the Republic of Kiribati. The objectives of this mission include the high-quality education of 13 students in both science and policy aspects of PIPA as well as scientific goals, which will be detailed in the coming weeks and months here on this blog.

This post comes from research intern Luke Faust.

Friday July 25, 2014

We have arrived at Orona after a brief two day stint at sea.

View from the porthole at sea

Along the way we did five hydrocasts and Neuston net tows, plus a few MOCNESS deployments and meter net tows. We sampled the waters just off of each island we visited plus a double station our one full night at sea, one at night and one during the morning. These are among the most important measurements we will make while at PIPA. Many of the differences we detect are small from station to station, but from a large scale view the patterns should become clear.

Deploying nets from the Robert Seamans

Another island, Birnie, lay between us Kanton and Orona only a few miles east off out of our way. Unfortunately the wind was coming directly from the east as well and sailing into the wind is very difficult and not something we were going to do. Instead we motored most of the way there, reaching Birnie early on the 24th. In many ways Birnie is very similar to Enderbury. Like Enderbury it is a small island with little vegetation and large populations of seabirds. Birnie was also part of the same rat eradication that Enderbury had in 2011. It was not successful at Enderbury so we were very interested to see what Birnie's rat status was. Although no one went onshore and we only stopped at Birnie for an hour of bird observations and a deployment station, we saw clear signs that the eradication was successful.

Christmas shearwaters roosting | Photo: Duncan Wright via Wikimedia Commons

Close to ten different Christmas shearwaters were flying a little offshore, and since they make their nests in burrows in the ground, are especially vulnerable to rats. So their presence at Birnie is an indicator that there are no longer any rats on that island and that the eradication was successful.

Luke Faust

7/15/14

SEA 2014: PIPA Arrival! (July 15)

Tuesday, 15 July 2014

We crossed the equator on Sunday morning, the day we entered into PIPA. There is always a celebration of the event, crossing the line is a big thing for a sailor, for the first time in particular. Of course around the ship nothing changes, the same trade winds push us along, the same waves stretch into the horizon. Drawing lines into the high seas can seem like a funny business!

And on some level that is what PIPA is, a square patch of the ocean marked by lines drawn into the water. When we protect sensitive areas on land, understanding boundaries is easy. On this side of the fence big redwoods you mustn't touch, on this side a pasture for dairy cattle. The trees stay put, the situation is pretty stable.

Not so in the ocean. The ground is more than three miles below the ship and remains less known to us than the surface of Mars. No, what we really seek to protect here is in the shallow ocean, all the life that it nurtures and supports, from seabirds to tuna, from whales to the manta rays and the turtles. These are the iconic species of course, but in one way or the other their existence is predicated on an ocean ecosystem of plankton.

A detail of a small lanternfish (Myctophid) from our meter net plankton tow this evening.
These fish migrate up and down in the water column, spending the night feeding on
zooplankton close to the surface but at night swimming down up to 900 meters deep.

Plankton are those animals and single-celled algae that drift with the ocean currents. The phytoplankton, microscopic algae that photosynthesize, are the grass feeding this vast ocean savannah with its own equivalents of wildebeests and lions. One crucial problem with this metaphor exists, though. As ocean currents respect no boundaries, neither does all this oceanic life they transport. So what do those lines in the ocean really mean, then? What are we protecting here exactly?

Turns out you have to change your perspective here to include the notion that even in the ever flowing ocean there can be persistent hotspots of life that remain in the general location. These hotspot oases are fully aquatic, so water is of course not the limiting substance for growth here as it is in the desert. No, the limiting factors here are nutrients, mostly Nitrogen and Phosphorus (and Iron in the Equatorial Pacific) — the same resources we feed our terrestrial gardens! These hotspots tend to form wherever ocean currents act to bring these limiting resources to the sunlit surface ocean where their constant supply is needed to fuel the growth of the Phytoplankton.

Are there many such hotspots in PIPA? It turns out that the northern boundary of PIPA encompasses a portion of major ocean current called the Equatorial Undercurrent. This current is a product of our planetary climate system, persists over time, and is responsible for constantly pumping nutrients to the surface ocean. You could almost think of the northern fringes of PIPA as this lush rainforest at the edge of a savannah, a wall of green foliage. Today as we've been sailing through the tail end of this edge we’ve witnessed schools of tuna dashing after their pray, large flocks of seabirds following these feeding schools, and even a thresher shark lazily warming itself after a long dive, its long tail fin sticking out of the water as we sailed by.

We expect to find other such hotspots, aligned with seamounts and islands that act in concert with the currents to similarly help fertilize the surface ocean. We'll look for them as we sample, using our current meter to map the currents, our rosette water sampler to draw nutrient and chlorophyll samples, and our plankton nets to sample for the small fish and even smaller zooplankton, the necessary precursors for those big iconic species like sharks and dolphins to exist.

All of this means a lot of hard work of course, and once inside PIPA we’ve begun spending a lot more time on our sampling efforts. At night, the instrument and MOCNESS deployments have gone on from 9 pm to around 3:30 am. Daytime stations are shorter, from 10 to noon, though samples drawn during these stations keep the lab busy around the clock. Here the training we’ve done in the past two weeks really pays off — the students are an integral part of the lab workflow now. During our daily ships meetings we discuss aspects of our results and talk about the things to come.

Another short three weeks and we'll know much more about this aspect of PIPA. And with that I’ll sign off and head into the lab for our night station. We’ll catch some plankton, and I’ll include a picture of some of them with this post!

Jan Witting,

Chief Scientist

7/12/14

SEA 2014: The MOCNESS monster (July 12)

Saturday, July 12

As we close in on our crossing of the equator, we experienced our most exciting day today in all aspects of ship life. Throughout the first two weeks, we deployed two different scientific instruments daily, a Neuston net, a meter wide net that collects zooplankton from the surface of the ocean, and the hydrocast, which is a series of twelve seawater collection tubes that open at different depths. Over the past we days we have been adding a few new instruments. Early this morning we deployed our third Argo float when we crossed the 2.5° parallel. These are similar to the hydrocast, in that the measure parameters of the ocean water at different depths such as salinity and temperature. But these Argo floats part of a network of thousands of robotic floats around the world’s oceans that can raise and lower themselves in the water column, collecting and transmitting data for up to seven years.

Working the sampling nets on deck

Later this morning, after a misfire yesterday, we successfully deployed our first MOCNESS (Multiple opening and closing nets and environmental sampling system). It is similar to the Neuston net but much more advanced. The MOCNESS is a series of nets that can be opened and closed at different depths, sampling the zooplankton not just at the surface. Different organisms prefer different depths and conditions so the MOCNESS allows us not only to sample the lower depths, but also to separate out what was caught where. Once we are in PIPA, the MOCNESS will be an important part of our scientific study of the area.

Pilot whale

The MOCNESS itself would have been enough to make this a remarkable day, with everyone looking forward to its appearance with much excitement. But the MOCNESS pales in comparison to a pod of five or ten pilot whales, the first mammals we’ve seen other than ourselves in two weeks. Pilot whales are small whale with very round head, almost swollen looking. On the whale-dolphin spectrum they fall close to the dolphin side, having the general size and shape of a large dolphin. The pod followed behind our ship for close to twenty minutes, coming to the surface and swimming right alongside our ship. A ray was spotted soon after, along with five or six different bird species, making this by far our most biologically active day.

After doing our weekly thorough clean of the ship, we were surprised with a swim call from the captain. The waters were calm enough that we were able to stop the ship and all get in the ocean for a swim. It felt so refreshing to wash off and finally get in the ocean. It is pretty cool to think that below us was close to 5,000 meters of water between us and the ocean floor. Early tomorrow morning we expect to make our crossing of the equator. A few days after that we will enter PIPA finally before spending the next three weeks in its waters. Our exact plan for those three weeks is still relatively unclear, as we do not know what conditions will be like and how many landings we will be able to make. But our general plan is to go to Enderbury, Kanton, Orona, possibly a trip up to Winslow Reef, and then Nikumaroro before heading out to American Samoa. We will spend three days on and around each island doing both terrestrial and marine work. Our transit time between islands will also involve intense data collection as we try to get an idea of what the waters in PIPA are like and the connectivity between islands.

Since this is the first oceanographic research trip to PIPA that will be our primary research focus while we are there. But there are still many more miles to go before we arrive, including an equator to cross.

Luke Faust

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The Phoenix Islands Marine Protected Area (PIPA) is the one of the largest marine protected areas in the world and the largest and deepest World Heritage site on Earth. It was created in 2008 by the Pacific Island nation of Kiribati with support from its partner organizations, New England Aquarium and Conservation International. The Aquarium is grateful to the Prince Albert of Monaco II Foundation, The Robertson Foundation, GoPro, The Explorers Club and many others for helping to support this expedition.

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Expedition Partners

Woods Hole Oceanographic Institution

Team Members

Randi Rotjan, PhD

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Dr. Randi Rotjan is a research scientist at the Aquarium, with expertise in coral reefs, symbiosis, and climate change. She coordinates the Aquarium’s research partnership with Kiribati on the Phoenix Islands Protected Area (PIPA) and co-chairs the PIPA Science Advisory Committee. She is the Chief Scientist for the current expedition to the PIPA, coordinating the expedition by satellite.

Sangeeta Mangubhai, PhD

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Dr. Sangeeta Mangubhai is an adjunct scientist at the Aquarium. She has been working with the Aquarium since 2000, during the first trip to the Phoenix Islands. This is her fifth trip to PIPA. She is the Chief Scientist onboard the expedition, working with 15 others onboard and Rotjan remotely to study the current El Nino and the impacts on PIPA marine life.

Simon Thorrold, PhD

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Dr. Simon Thorrold is the Director of the Ocean Life Institute and a Senior Scientist in the Biology Department at the Woods Hole Oceanographic Institution (WHOI). He serves on the Science Advisory Committee for the Phoenix Islands Protected Area. He is a co-organizer of the 2015 PIPA Expedition, working closely with Rotjan and Mangubhai to ensure a successful voyage.

View a list of previous blog authors here.

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New England Aquarium