And the winner is...nutrients!

Carolyn concluded her artificial seagrass unit (ASU) experiment in Florida Bay last week (despite TS Fay's best efforts to deter us). The objective of the study was to determine if seagrass epifauna responded to nutrient additions because of changes in the food resources (epiphytes) or because of changes in the canopy complexity as faster-growing, highly branched species proliferated. We are particularly interested in grazing crustaceans like grass shrimp (left), but other species like nudibranchs (below) were also present.

We installed ASUs with dense and sparse canopies made from polypropylene ribbon. Half were enriched and half were not. After 3 months, it seems that epifauna were more abundant in enriched plots, regardless of canopy density. This is a qualitative assertion, however--canopy effects may not be as strong (and therefore not as visually obvious) as nutrient effects. Carolyn is looking forward to many weeks of sorting, identifying, and enumerating these creatures to find more definitive answers to our questions.

Three sites, three storms

The water and sky meet seamlessly--only a few mangrove islands and cotton ball clouds reveal the transition. Such was the scene in Florida Bay last week, before TS Fay swept us out of our study site. This is the third tropical storm to hit one of my study sites in the last month: Dolly in Pt Aransas, Edouard in Pt Aransas, and now Fay. None of the storms have been serious, and aside from the disruptions, our work has gone on. Heroic efforts on Carolyn's part ensured that the artificial seagrass experiment was brought to completion (pictures here), despite the storm. Did nutrients or canopy density have a stronger impact on epifaunal communities? Stay tuned...

Why is this Spartina falling down?

Yesterday, while surveying a brackish marsh restoration site near Port Arthur, Texas, we noticed that some of the planted Spartina alterniflora appeared to be falling down (left), especially around the edges of constructed mounds. Although the plants grew quickly (they are only about a year old!), is erosion around the edges of the mound going to undermine the long term success of these plantings? We noticed that mounds with fill added so that the sides are less steep seemed to have more upright plants (below). These shallower areas, however, had extensive cyanobacterial mats (green mats in the water in the picture below). What are the impacts of dense cyanobacterial mats on the animals in this system?

Coastal Ecologist positions at TPWD

Texas Parks & Wildlife Department is hiring two Coastal Ecologists. Full job descriptions are posted here.

Postdoc and grad student positions

Postdoctoral Researcher: Wetland Restoration Ecology

Department of Marine Biology, Texas A&M University at Galveston

A postdoctoral researcher position is available to work with Dr. Anna Armitage and Dr. Antonietta Quigg in the Department of Marine Biology at Texas A&M University in Galveston. The associate will take a leadership role with a two-year project assessing the effects of landscape engineering (e.g., sediment source, hydrology) on restored brackish marsh ecological functions. Possible research fields include patterns of productivity, carbon sequestration, and the development of food webs in restored marshes.

Required qualifications: Ph.D. or equivalent in Biology, Ecology, or related field.

Additional qualifications desired: Experience with field ecology methodologies, community ecology, use of stable isotopes, productivity measurements; strong writing skills.

Special requirements: Physical ability to conduct research in the hot and humid conditions typical of Gulf of Mexico coastal wetlands.

Responsibilities: The associate will be expected to conduct independent research, provide some assistance to graduate students, write research articles, and generate reports for the funding agency.

Start date is September 1, 2008. For full consideration, submit applications by July 1, 2008. Submit TAMU application, statement of interest and experience, and CV at the online submission website, tamujobs.tamu.edu (NOV# 081262). In addition, please have three references submit letters of recommendation directly to Dr. Anna Armitage (armitaga@tamug.edu) with a cc to Betty Thompson (thomspob@tamug.edu).

Texas A&M University is an Affirmative Action/Equal Opportunity employer committed to excellence through diversity and particularly invites applications from minorities, women, veterans and persons with disabilities.

Graduate student: Wetland Restoration Ecology

Department of Marine Biology, Texas A&M University at Galveston

We are seeking a M.S. or Ph.D. student to participate in a two-year project assessing the effects of landscape engineering (e.g., sediment source, hydrology) on restored brackish marsh ecological functions. Possible research fields include patterns of productivity, carbon sequestration, and the development of food webs in restored marshes.

Required qualifications: B.S. or equivalent in Biology, Ecology, or related field.

Additional qualifications desired: Relevant coursework or experience with field ecology methodologies, community ecology, use of stable isotopes, productivity measurements; strong writing skills.

Special requirements: Physical ability to conduct research in the harsh heat and humidity typical of Gulf of Mexico coastal wetlands.

Responsibilities: The graduate student will be expected to conduct independent research and assist with generating reports for the funding agency.

Desired start date is Spring 2009. Application deadline is July 2, 2008 or until a candidate is selected. Send statement of interest and experience, CV, unofficial transcripts, GRE scores (if available), and three letters of reference in electronic format to Dr. Antonietta Quigg (quigga@tamug.edu).

Texas A&M University is an Affirmative Action/Equal Opportunity employer committed to excellence through diversity and particularly invites applications from minorities, women, veterans and persons with disabilities.

Friendly frog, angry alligator

Allison took a team out for her first sampling trip in Armand Bayou today. In order to assess how plants mediate water quality in the Bayou, we collected plant, soil, water, and pore water samples along a gradient away from a sewage outfall. At least that was the idea. The first five stations went fairly smoothly, once the pore water sampling protocol was worked out.
But on our way upstream we encountered a female alligator who made it very clear that we were not welcome in that area (probably a nest nearby). She herded us several hundred meters downstream. We might have felt less vulnerable if we weren't in canoes, eye-level with the gators. We'll try to use a pontoon boat for the next trip.
Other wildlife was more friendly, like this frog that hopped along the gunwale, up onto my knee, and then back into the water.
UPDATE: Turns out, the pontoon boat was in the shop. But, a smaller team was able to squeeze by the alligator the following day and complete the sampling upstream. Good work!

Artificial seagrass has been deployed

After many, many hours of hard work by the Seagrass Rangers in Jim Fourqurean's lab at Florida International University, Carolyn and I were able to start our first artificial seagrass experiment in Florida Bay. We are investigating whether epifauna respond more to canopy complexity or to epiphyte abundance (which we will increase with nutrient addition). Below is an artificial canopy, painstakingly constructed by hand (thanks everyone!!) from polypropylene ribbon, cable ties, and egg crate from light fixtures. This is a dense canopy with short Halodule wrightii and tall Thalassia testudinum. After just a few hours in the field, the "leaves" were already getting colonized by oysters (Pinctada longisquamosa). See more pictures here.