Arriving at Aeropuerto Ecológico Galápagos Seymour on Baltra Island, our team encountered a surprising scene. The terrain was rugged, brown, and devoid of much vegetation, contrasting sharply with the turquoise and deep blue hues of the nearby sea. Our research group, the Sandin Lab at UC San Diego’s Scripps Institution of Oceanography, focuses on studying coral reefs and their development over time in various environments. Our usual field sites are lush, green, tropical islands, so this landscape initially seemed distinctly unfamiliar to us.
After extensive planning, my colleague Nicole Pedersen and I finally reached our destination. Our purpose was to participate in marine monitoring as part of the pre-restoration surveys for the Floreana Island-Ocean Connection Challenge Project. This initiative, a collaboration between Scripps Oceanography, non-profit organizations Re:wild, and Island Conservation, aims to eradicate invasive species from islands to restore native wildlife, coastal ecosystems, and local communities.
We carried multiple bags filled with SCUBA and underwater imaging equipment, transferring them from bus to ferry and then into a taxi for the journey from the airport to the town. The drive was captivating as we traversed through various microclimates that starkly contrasted the landscape we had encountered at the airport. It became evident to us quickly that this field expedition would be unlike any we had experienced before.
With the assistance of our partners from Island Conservation, who introduced us to the Marine Biodiversity Research team at the Charles Darwin Foundation (CDF), we gained valuable new collaborators. Following a few days of training and familiarization, we prepared to board our research vessel and commence gathering a comprehensive set of data for our baseline pre-restoration monitoring. Over the next 8 days and nights, we diligently collected and analyzed data to assess the impact of the restoration efforts on fish and benthic communities, as well as nutrient availability in the nearshore marine environment.
Our approach employs a Before-After Control-Impact (BACI) experimental design to evaluate the effects of the island restorations. This method accounts for any natural or pre-existing differences between sites, providing an accurate estimation of the actual impact of the restoration. To facilitate this, we identified Española Island as a suitable control site, similar to Floreana (the restoration site), in terms of environmental context—ensuring consistency in meteorological, oceanographic, and geological conditions throughout the monitoring period. This consistency is crucial for distinguishing between changes caused by restoration efforts and those stemming from natural conditions, particularly important given the current El Niño conditions affecting the islands.
The BACI design's Control-Impact component is fulfilled by monitoring both the control and restoration islands, while the Before-After component involves collecting data before and after the restoration at comparable sites on each island.
The days were arduous and extended, but fortunately, the CDF team operated with remarkable efficiency and possessed an intimate knowledge of the marine terrain. One of the many advantages of collaborating with CDF was accessing a subset of their annual marine monitoring sites for our impact assessments, providing a wealth of historical data to establish a solid baseline. Another intriguing aspect of our data collection involved complementary terrestrial monitoring data gathered by Island Conservation and local partners. These datasets will detail the effects on the terrestrial landscape. By integrating these distinct datasets, we, as scientists and conservationists, can gain deeper insights into the island-ocean relationship and how island restorations influence the nearshore marine environment.
The dives we conducted around Floreana, designated as the restoration island, and Española, identified as the control island, were remarkable and markedly different from the tropical environments typically monitored by our lab—most notably, the striking difference in water temperature. Cooler water temperatures had a notable impact, especially during prolonged periods in the water. The composition of the seafloor environment also presented stark contrasts, particularly the minimal live coral cover, although some sites featured sizable colonies of Pavona coral. Unlike the calcium carbonate structures we're accustomed to, the reefs were predominantly composed of volcanic rock.
The size and abundance of herbivorous fish were astonishing. During our imaging of the seafloor, there were instances where large schools of Prionurus laticlavius, commonly known as razor surgeonfish, swam through the area, completely obscuring our view. During these moments, we had to pause photography until the fish moved on.
As part of our data collection strategy, we are gathering macroalgae samples for subsequent isotope analysis. The results from this analysis will provide insights into the origin and availability of nutrients in the nearshore marine environment. Nutrients, particularly their transfer from the terrestrial to the marine environment, are crucial components of the island-ocean relationship.
Initially, I was surprised by the scarcity of fleshy macroalgae available for collection. However, upon observing the large schools of herbivorous fish mentioned earlier, I understood why I was encountering difficulties in finding sufficient quantities of algae.
One evening, while anchored near Floreana, our team was diligently downloading and entering data, as well as drying and processing algae samples, when we were suddenly startled by loud thuds against the side of the boat. We hurried to the back deck to witness fascinating shark feeding behavior. We observed approximately 50 to 60 Carcharhinus limbatus, commonly known as blacktip sharks, chasing flying fish into the boat's hull. The impact momentarily stunned the flying fish, triggering a feeding frenzy among the sharks!
The shark feeding incident was certainly memorable, but our most unforgettable experience in the water came from interacting with a curious, playful, and somewhat mischievous sea lion. While we were busy capturing images for our large-area imagery models—a digital representation of the reef used for further analysis—we noticed several young sea lions darting around, inspecting us with curiosity. Despite feeling a bit startled and apprehensive (given warnings about potential aggression), we continued our dive.
During the dive, we realized one of our corner markers, used to guide image collection, had gone missing. As I checked the remaining markers, I spotted a sea lion swimming up to one, grabbing it in its mouth, and swimming away! To our surprise, this playful sea lion had actually taken two of our markers. I followed it as it swam about 5 meters away and placed both markers neatly beside each other. We retrieved them, but the sea lion continued to eye them mischievously.
Throughout the remainder of the dive, we had to remain vigilant against the playful attempts of these thieving sea lions. It was a delightful and unforgettable experience for both Nicole and me, one that we will cherish for a long time.
Being able to observe and collect data in the Galapagos is particularly thrilling, especially given the IOCC project. This initiative represents a novel integration of rigorous scientific research and effective conservation practices, bridging the divide between marine and terrestrial conservation efforts. Working in this new environment alongside our partners invariably yields fresh observations and insights.
In addition to collaborating with the exceptional scientists and conservationists at CDF, I am particularly eager to delve into the data. Quantifying the connections between islands and oceans, and assessing the beneficial outcomes of island restoration initiatives, promises to reveal significant findings that can inform future conservation strategies.
