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Subtidal Community Surveys sampling design Introduction The intent of the monitoring program is to characterize the structure and dynamics of a kelp forest community. For this reason surveys are designed to sample a large number of ecologically and economically important species throughout the entire area of a kelp forest. In addition, we quantitatively characterize reef attributes (depth, substratum type, relief) that may explain spatial patterns of variation among samples.
For further information see the recent description of the PISCO subtidal monitoring program provided to the Cooperative Research and Assessment of Nearshore Ecosystems (CRANE) program Fish Survey Design
To assure that the 3-dimensional habitat created by kelp forests is sampled thoroughly, fish transects are stratified across the face of the reef (alongshore and cross-shore) and vertically through the water column. In each of the two areas that constitute a site, three transects are sampled in each of four zones (see fish sampling schematic above and map-view diagram below). The zones are stratified to encompass the offshore edge of the reef, the middle of the reef, and as shallow inshore as practical. For example, for a maximum depth of 20 meters (m) the depth zones would be 5, 10, 15, and 20 m. If no appreciable depth stratification is present, then the stratification is based on proximity to the outer edge of the reef and the shore. In each zone, three randomly located transects are sampled along isobaths (constant depth) parallel to shore. In cases where a reef does not extend very far offshore (e.g. narrow, steep reefs found in the Channel Islands), it may be unsuitable to sample four depth or distance strata. In this case, a modified sampling procedure is done based on three areas and two depth zones. In this case, 4 randomly located transects are sampled in each of two depth zones in three areas resulting in 24 transects.
Fish sampling methodologyThree portions of the water column (bottom, midwater and canopy) are sampled by two divers along each transect (see figure to the right). Both divers in the team identify, count and size all conspicuous fishes on each 30 m long x 2 m tall x 2 m wide transect. If gender is visually distinguishable (e.g., kelp greenling or California sheephead), this is recorded as well. Divers estimate total length (TL) of small fish (< 20 cm TL) to the nearest cm, and larger fish (> 20 cm) to the nearest 5 cm interval, as they reel out a 30 m tape. Fish surveys take place from approximately mid-August through October. Four divers can sample 24 transects (combined bottom, midwater and canopy) at one site within one day. Canopy surveys are timed to capture netannual recruitment of reef fish that settle to the kelp canopy. As a result, in central California, canopy surveys are conducted separately and later in the season than bottom-midwater surveys. In Southern California, canopy surveys are conducted simultaneously with bottom-midwater surveys. When conducted separately, canopy surveys (24 transects per site) are stratified across the reef identical to that of bottom transects, sampling the top 2 m of the water column (0-2 m depth) only. Algae and Invertebrates Survey Design
To assure that the entire kelp forest is sampled representatively, benthic transects are stratified across the face of the reef (alongshore and cross-shore). In each of the two areas that constitute a site, two transects are sampled in each of three zones (see Algae and Invertebrate Sampling Design schematic above and map-view diagram below). The zones are stratified to encompass the offshore edge of the reef, the middle of the reef, and as shallow inshore as practical. For example, for a maximum depth of 20 meters (m) the depth zones would be 5, 12.5, and 20 m. If no appreciable depth stratification is present, then the stratification is based on proximity to the outer edge of the reef and the shore. In each zone, two randomly located transects are sampled along isobaths (constant depth) parallel to shore. In cases where a reef does not extend very far offshore (e.g. narrow, steep reefs found in the Channel Islands), it may be unsuitable to sample three depth or distance strata. In this case, a modified sampling procedure is done based on three areas and two depth zones. In this case, 2 randomly located transects are sampled in each of two depth zones in three areas resulting in 12 transects.
Swath methodology
The purpose of the swath sampling is to estimate the density of conspicuous, solitary and mobile invertebrates as well as specific macroalgae. Individual invertebrates and plants are counted along the entire 30 m long x 2 m wide transect. Typically, a diver slowly swims one direction counting targeted invertebrates and then swims back counting targeted macroalgae. (See the swath datasheets for species targeted by this sampling method.) Cracks and crevices are searched and understory algae are pushed aside. No organisms are removed. Any organism with more than half of its body outside the swath is not counted. Transects are divided into three, 10 m segments. Only Macrocystis plants taller than 1 m are recorded. The number of stipes at 1 m above the substrate on each Macrocystis plant is entered on the datasheet. Nereocystis, Pterygophora, Laminaria setchellii, and Eisenia arborea must have stipes taller than 30 cm to be counted. Only Cystoseira osmundacea plants greater than 6 cm wide are recorded. Laminaria farlowii must have a blade greater than 10 cm wide. All plants of Costaria, and Alaria are counted. Swath sub-sampling
Very high densities of some species of invertebrates and algae prohibit enumeration along the entire length of a swath. We use a variable area sampling method in these cases. Within each 10 m increment (0-10, 10-20, 20-30) along a transect, divers enumerate organisms until the species threshold abundance (thirty individuals) or the end of the 10 m segment is reached. If the threshold abundance is reached, the diver records the distance they have sampled to that point along the transect and stops counting that species until the next 10 m segment. Uniform point contact methodologyUniform point contacts (UPCs) are used to estimate the percent cover of species and reef attributes along each 30 m long transect. Divers record three types of information beneath 60 points located at every half-meter along the transect: 1) substrate type, 2) physical relief, and 3) percent cover of space-occupying organisms. The percent cover of space-occupying organisms is estimated by recording what is directly under each point. The purpose is to re-create a two-dimensional, "photo style" representation of the percent cover of organisms that are directly attached to the primary substrate. Therefore, epiphytes, epizooids, and mobile organisms are not included. Algae whose blades are under the point but are attached somewhere else on the primary substrate are included. There are three exceptions that we have labeled "superlayers". If points overlay blades of Laminaria spp., the abundant sea cucumber Pachythone rubra or brittle stars, the blade or animal is removed and the species or substratum beneath it is recorded AND noted in the "superlayer" column on the datasheet. The UPC datasheets include categories for all non-motile, benthic invertebrates and algae. Reef attributes are also noted for each point. Substrate type is recorded as sand, cobble (< 10cm diameter), boulder (10cm - 1 m diameter) or bedrock (> 1 m diameter). Physical relief is measured as the greatest vertical relief that exists within a 1-meter wide section across the tape and a 0.5-meter section along that tape that is centered over the appropriate point. Quadrat methodologyPISCO U.C. Santa Barbara also uses quadrats to estimate the cover and density of a) small invertebrate species, b) recruit invertebrate and macroalgal species, and c) cryptic or small benthic fishes. Divers carry a three-sided 1 square meter PVC folding quadrat and place it on the bottom adjacent to the tape at meters 2, 7, 12, 17, 22 and 27 m. The quadrat is positioned so that the tape completes the fourth side. The diver then records the number of all targeted species in the quadrat. Substrate beneath the understory is searched but no organisms are removed.
PISCO Subtidal Survey TrainingPISCO subtidal surveys are designed to rigorously sample temperate rocky reef communities. Consequently divers must be well trained in species identification and survey techniques. Diver's skill levels must meet a rigorous standard in order to participate in data collection for the surveys. PISCO ensures that all divers are competent in the survey techniques by providing intensive training and evaluation prior to the survey period. To allow rapid specialization by the divers, the survey is divided into two groups (Fish and Algae/ Invertebrates). Divers are trained in one to two weeks on each subject in an intensive classroom and field training course. PISCO training takes them through species identification and survey techniques (e.g. size and abundance estimation, transect placement and sampling procedure). Divers may complete both courses and become trained in the entire survey technique in as little as two to four weeks of intensive training. Below we have provided downloads of the materials used during PISCO survey training. Also, see the preliminary checklist for an outline of the necessary materials and equipment needed for conducting the surveys, which can be used as a guideline for equipment needed in the field. Fish Training
Classroom materials - Fish sampling
Schedules Example fish training syllabus (.doc) Fish transect identification material
Daily fish training lectures (PowerPoint) Algae and Invertebrate Training
Classroom materials - Invertebrate and algae sampling
Schedules Example algae/invertebrate training syllabus (.doc) Swath transect identification material
Uniform Point Contact (UPC) identification material
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crane_protocol.pdf
UCSB Fish Datasheet
At each monitoring site, visual surveys by scuba divers are used to quantify the size structure and density of fish populations and the species composition and structure (i.e., relative abundance) of fish assemblages. 
Bottom transects sample the bottom 2 m of the water column, contiguous with the reef surface, and the midwater transect is located just above and slightly offshore and forward of the bottom transect. The height of the midwater transect varies as a function of bottom depth (4-6 m above the bottom for bottom depths of 10 m or greater, 2-4 m above the bottom for bottom depths of 6 m or less). In cases of where poor visibility does not allow divers to maintain visual contact, midwater transects are run closer to the bottom. Bottom and midwater transects are sampled simultaneously by two divers. After completion of bottom and midwater transects, divers move up to the canopy and moving in the opposite direction, count fish in the top 2 m of the water column (0-2 m depth) only. One diver samples the fish while the other diver estimates percent canopy cover along the 30 m long transect. 
At each monitoring site, visual surveys by scuba divers are used to quantify the size structure and density of macroalgae and invertebrate populations and the species composition and structure (i.e., relative abundance) of their assemblages.
