Thursday, November 20, 2008

Hurricane impacts in brackish marshes and other questions

The restoration site at Port Arthur survived Hurricane Ike fairly intact. There wasn't much debris, and by the time we returned to the site, water levels had returned to normal. Salinity was high, though, about 15 ppt, when the site is normally about 3-5 ppt. Some species of plants looked fine, but others were stressed. Interestingly, some stands of Spartina alterniflora seemed fine, but others were dying. Is this a difference between native and non-native strains? Or is it a function of plant age?
Planting stands of Spartina alterniflora in this restored site results in robust monocultures of S. alterniflora. See the new species (an aster?) trying to recruit into the Spartina stand? Will it be able to establish in this dense stand? Does planting S. alterniflora limit plant diversity on a longer time scale?
One day, soon after the storm, I visited the salt marshes on Galveston's east end. I was stunned at the number of snails (Littorina) that were clinging onto the grass. It is not unusual for Littorina to climb up Spartina stems during high tide, but the density of snails at this site surprised me. Were they trying to get away from something?

More Hurricane Ike views: This house is "For sale by owner"
Boats on Sportsman Road
This just in: Plastic grows on trees

Thursday, October 2, 2008

Another side of Hurricane Ike

We've all seen a lot of pictures of the devastation to homes and businesses caused by Hurricane Ike. As a biologist, I see that damage and more. Here are some of the pictures you won't see on the news.

Many trees were still standing after the storm, but inundation by salt water killed them where they stood. The only plants that survived were native dune and marsh grasses.

The dunes on Galveston Island were badly eroded, but in some places with robust dunes, the vegetation held enough of the sand in place to prevent massive erosion. The beaches are ragged but still standing (and so are the building behind them). Beaches in front of the seawall had no vegetation to guard against erosion, and those beaches eroded and are now underwater.


Bread makers are generally not found on the beach.

Mardi Gras beads were strung over mangroves. Many mangroves survived, but the salt water inundation was hard on them too. Many are displaying salt burn like terrestrial plants.

Ok, this picture has been on the news, but it was too striking to pass by. I think it was Murdoch's souvenir shop. It is now a bird roost.

Our recycling center. Where am I supposed to take my plastics now?

The TAMUG campus had relatively minor wind damage and didn't flood. We even got internet back yesterday (but no phones yet, so don't call me). Because the Galveston city infrastructure is in such bad shape, classes have been relocated to College Station for the rest of the semester. Research goes on for now in a modified fashion (nothing stops the science!), and we expect to be fully operational again by January.

Sunday, August 24, 2008

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.

Thursday, August 21, 2008

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...

Wednesday, July 16, 2008

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?

Monday, July 14, 2008

Coastal Ecologist positions at TPWD

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

Tuesday, July 1, 2008

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.

Thursday, June 12, 2008

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!

Sunday, May 18, 2008

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.

Friday, May 9, 2008

Thanks to TGLO for a research grant


The Texas General Land Office has awarded a research grant to myself and Dr. Antonietta Quigg to study the efficacy of different restoration techniques in brackish marshes in north Texas. Mounds were created in degraded open water habitat using different pumping and dredging methods and sediment sources. We will be studying these restoration methods using surveys and field experiments. Potential grad students and postdocs: keep an eye on this blog for upcoming job postings...

Wednesday, April 16, 2008

What comes out of here?

It looks so innocuous. It's just a small inlet leading into Horsepen Bayou, a tributary of Armand Bayou. But this inlet is actually fed by an outfall from a sewage treatment plant just a few hundred meters upstream.

The sewage is treated, but it's unknown how many nutrients the outfall contributes to the Bayou, or how its output influences the growth and establishment of restored marshes downstream or the invasive plants that are spread throughout the Bayou.

Welcome to Allison Parnell--she will be seeking answers to these questions and more for her master's thesis.

Thursday, March 6, 2008

What would you do here?

This is a brackish marsh restoration site in the Lower Neches. Multiple restoration techniques were employed. Some sections were constructed mounds from dredge spoil:
Others were excavated mounds:
And others were mounds surrounded by dredge fill:

What are the advantages and disadvantages of these methods? Which are the most ecologically successful? These are the next questions my lab will address. See more photos here.

Wednesday, January 2, 2008

Congratulations Carolyn!

Congratulations to incoming Ph.D. student Carolyn Weaver, who was awarded a semester of support from the TAMUG Interdisciplinary Fund. Way to go!