Sailing for Seagrass

Kate Aubrey – Earthwatch Australia’s Public Program and Marketing Manager – recently returned from Seagrass Monitoring Expedition in Moreton Bay, Queensland – Sailing for Seagrass. She mapped the seagrass meadows in Moreton Bay with seven volunteers.

There are some things I honestly never thought I would write home about and “seagrass is cool” is certainly one of them. To no surprise to the scientists who dedicate their time researching this underwater world, all seven Earthwatch volunteers joined me in my newfound appreciation of the ocean’s grass.

Kate

Seagrass is a flowering plant that has adapted to living in the ocean. That means, it lives its full life cycle, including flowering and pollination all in the harsh oceanic conditions. Cool right?

If I haven’t convinced you yet, how about the fact that the “Sea Cow” (aka. Dugong), our only herbivorous marine mammal, depends almost entirely on seagrass as its food supply. It grazes on seagrass similar to how the cows graze on grass, except that the dugong removes the whole plant leaving distinct trails along the ocean floor.

Despite not seeing a dugong on the expedition, we did observe these dugong trails and saw more than 40 turtles during the trip.

Arrival

The team met on 16 August at Tangalooma Launches and ferried over to Moreton Island before settling into the well-maintained Villas at Tangalooma Resort. Lead scientist, Dr James Udy, co-scientist Paul Maxwell and Mark Gibbs, our skipper, greeted us at the Villas. James then provided an insightful briefing of the research priorities and activities.

Resort[2]

The first evening we participated in the Dolphin Feeding program managed by Tangalooma Resort. The volunteers had their doubts about the concept, with questions about the legitimacy of feeding wild dolphins. Their concerns were eased when the Resort staff explained the program is a way to educate tourists on the impacts of marine debris and explained the strict guidelines in feeding the dolphins. For example, they are only fed 5% of their daily diet and juvenile dolphins are excluded from this luxury, to ensure they develop their hunting capabilities.

The dolphins come into the beach each night and ‘line up’ into the same rows before being fed and scooting off to hunt – such creatures of habit!

3-Dolphon

The Research

The real work began on day two. We were split into two teams Pelagio (the research speed boat) and Velella (the catamaran). Paul and I were the Pelagio crew team and James and Mark held the reigns on Velella.

Each day the volunteers were able to swap between the two boats. Partly to mix up the research activities, allow their wetsuits to dry and enjoy the sundowner speciality on Velella – that the research vessel couldn’t offer.

The activities varied however, the overall goal was consistent. We were mapping the seagrass meadows within Moreton Bay. As turbidity increases and light penetration is reduced, the depth at which seagrass can grow declines. By measuring the depth at which seagrasses grows overtime, we can provide scientists a good indicator of water quality.

There has been a significant decline to seagrass meadows throughout the bay, and research shows that if the amount of sediment is not reduced this decline will continue significantly impacting the sea-life that depends on it.

On Velella, volunteers helped lower an underwater camera down to the oceans floor to observe, what species and density of seagrass was prevalent and the sediment type. Recording sediment type was a highlight with people yelling out scientific terminology such as ‘muddy-sand’ or ‘sandy-mud’ or better yet, sand with muddy sand – I could go on, but I’ll spare you.

6-Dropping-the-camera

The species and density guides were a useful tool to determining what species was what. Towards the end of the trip everyone’s ‘seagrass eyes’ were sharpened and the guides were not seen again.

The speedy versatile vessel, Pelagio, would take us into shallower depths to snorkel and take seagrass cores, record observations for mapping and set cameras to observe sealife. Coring consisted of a two-person buddy system, one with a 20cm pipe serrated on one side to cut into the seagrass and the other with a sieve for removing sediment from the sample.

The buddy also served their purpose to keep the buoyant snorkeler down as they attempted to push into the ocean floor to cut their sample. The not-so-graceful duck-diving coring manoeuvre took a certain level of skill, perseverance and teamwork.

The go-pro’s were held down with bricks and recorded bait that was placed a foot in front of it and most evening ‘movie nights’ involved everyone huddled together to see what fish and species had a sneak peek. There was a curious cormorant that came down for a snack – twice!

The days were long and certainly cold, however, I went home with a new understanding and appreciation of the role and beauty of our oceans grasslands.

8-Seagrass[2]

See more from Channel 7 that came out for a few hours to meet us one-day.

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