Reef Check

The Team.

Ideally, a team consists of 6-8 divers as well as the team scientist and the team leader or the dive guide. Each of the three categories (fish, invertebrates, and substrate) is handled by a two-person team during each survey dive. To maintain variety, each day the teams can change categories.

Preparations.

In order to prepare volunteers, we give a presentation during the afternoon or the evening before the survey to explain the process and show the indicator species that will be identified. And we clarify all questions again directly before the survey dive.

Prior to the survey dives, we go for a regular dive to identify once again the indicator species which will be included in the survey. For the survey, each diver receives a protected identification card for reference under water. The tables for entering the observed species and substrate are printed on A5-sized dive slates.

Surveys.

Each reef is measured at two depths (around 5 meters and around 10-12 meters), which usually occur on different days. The total time for a survey, from the arrival to the reef until the departure from the reef, takes about 3 hours. The individual teams require 60 minutes at the most. First the team scientist and a buddy place a 95 meter long transect line in the reef which has been marked with 20 meter segments from which the data will be taken. Each category will be assigned to a team of 2 divers, who will start the dives about 15-20 minutes apart.

FISH TRANSECT.

The indicator fish will be counted along the transect line in an area that includes 2.5 meters on each side of the line and up to 5 meters above the line. The “Fish-Team” starts its dive about 20-30 minutes after the transect line has been laid so that the fish have recovered from the disruption.

INVERTEBRATE TRANSECT.

The “Invertebrate-Team” starts their survey 20 minutes later on the same transect line measuring the invertebrate damage in an area 2.5 meters on each side of the transect line creating a 5 meter wide “transect-path”. In this case, each of the 2 divers surveys one side of the transect line. 
-> Images of invertebrate indicator species.

SUBSTRATE TRANSECT.

Another 20 minutes later comes the "Substrate-Team" which, with the help of a plumb, determines the type of substrate at every 50 cm along the transect. In this case, one diver swims along the transect line and signals the type of substrate to the second diver.

If you do not immediately understand everything, which is not a surprise given the special vocabulary, don’t worry as each Reef Check team includes a Team scientist who can answer any questions.

More details about the survey methods in Part 2.