Our team recently ventured out to our kelp restoration site off the coast of Hotham Sound to deploy some field sensors. But before we talk about sensors and data, we’re excited to share that after the kelp out-planting that took place in November and December last year, we’re seeing some impressive growth. The once seeded lines are now covered with long kelp growth spanning up two or three feet in length. We’re excited to continue to see the kelp grow and with the help of our new sensors, learn about any changes taking place in its local environment.  

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What was installed?

Kelp is a type of seaweed that is highly sensitive to environmental conditions, and maintaining suitable ocean temperature and pH levels are essential for growth and health. Currently the kelp is sitting 10 metres below the surface of the water, so our team installed temperature and pH sensors along the water column that the kelp will grow up along. This will keep us informed on the conditions our baby kelp is facing. By collecting data from-the-ground, our team can better understand the conditions of the site, how the kelp is performing, any risks that the restoration site might be subject to and whether the site is experiencing the positive outcomes we’re striving to achieve.

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Temperature

Kelp typically thrives in a specific temperature range. For many kelp species, this range is between 5 to 20 degrees Celsius , but the exact optimal temperature can vary depending on the kelp species. The temperature affects the metabolic processes of kelp, including photosynthesis and nutrient uptake. If the water temperature is too high or too low, it can negatively impact the growth and survival of kelp.

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pH (Acidity/Alkalinity)

Kelp prefers a pH range between 7.5 and 9.0. This is considered a slightly alkaline to alkaline environment. pH influences various biochemical processes, including nutrient availability and enzymatic reactions. Extreme pH levels, either too acidic or too alkaline, can stress kelp and hinder its growth.

In the context of kelp restoration, monitoring these levels helps ensure that the environmental conditions are suitable for kelp growth and development. If the temperature or pH deviates from the optimal range, corrective measures may be needed to create a more favourable environment for kelp.

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Kelp Impact on the Ecosystem

Conversely, the presence of kelp can have some effects on pH and temperature within an ecosystem. Although these effects are relatively minor compared to larger environmental factors, by measuring the environment with these localized sensors, we can see how the kelp is influencing its immediate surrounding conditions through its metabolic processes and interactions with the local environment. Here's how:

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pH:

Kelp, like other plants, undergoes photosynthesis, a process where they absorb carbon dioxide  and release oxygen. This uptake of CO2 can lead to a localized increase in pH during daylight hours when photosynthesis is actively occurring. During periods of low light or darkness, kelp undergoes respiration, releasing carbon dioxide. This can contribute to a decrease in pH in the surrounding water. Overall, the net effect of kelp on pH is often considered relatively neutral, and any fluctuations are typically confined to the immediate vicinity of the kelp bed.

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Temperature:

Kelp can provide shade to the surrounding water, reducing the penetration of sunlight. This shading effect can result in slightly cooler water temperatures in the shaded areas beneath the kelp canopy. Kelp beds may also provide some thermal buffering, helping to stabilize local water temperatures by reducing the impact of rapid temperature changes.

By measuring the pH and temperature along the kelp column, our goal is to get a sense of how the presence of kelp is also changing its environment. Regular monitoring using these sensors will allow us to make informed decisions and implement necessary interventions to support kelp ecosystems. The data from our sensors will be logged every 30 minutes and collected on a weekly basis.  

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ROV Data Collection

In addition to our water sensors, our team also deployed a Remotely Operated Vehicle (ROV). ROVs are typically used in deep-sea exploration and marine research for tasks that are too hazardous for human divers. These remotely controlled devices are operated by human pilots on the surface to collect important data. In our case, we used an ROV to collect substrate data, to look at the local flora and fauna and particulate at the site. By recording this information, we can compare the findings over the course of the kelp production. The ROV we deployed can go as deep as 1,000 feet and uses an HD camera with 4x 8,000 lumen lights on it!

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What’s Ahead?

We’re excited to see that our kelp restoration off of Hotham Sound is off to a great start, already showcasing impressive growth just months after outplanting. In the coming months, we look forward to the increased level of data that we will have access to through our newly deployed sensors and how we can take these findings to better understand and plan efficient kelp restoration projects into the future.

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