Race Rocks Long-Term Monitoring Programme

Dr. Jane Watson produced this report in the early 1980s.

What is the purpose of long-term monitoring projects?
Long-term monitoring projects are often used to follow changes in community composition or structure that occur over time. In this case you will be looking at natural changes in marine algae and invertebrate populations with respect to both long and short-term changes in water temperature.

How will this project be carried out?
You will be helping to establish the study sites which ultimately Pearson college will monitor two to three times a year. At least four of these sites will be at Race Rocks, others will be established at other sites that Pearson College divers visit regularly.

What will this involve?
Over the next three months we will be putting the permanently marked transects in. Once we have established all of the transects we will start to sample them. On each permanently marked transect Coast-watch divers will use randomly placed quadrats to estimate the abundance of selected invertebrates and algae.
In the lab the data will be entered and analyzed. These data should show how the abundance of many of many marine plants and animals change over time.
We will also be installing an underwater thermograph. This small instrument will record water temperature at predetermined intervals. Several times a year Pearson college divers will retrieve the instrument and down-load the data onto a computer. Changes in the composition of the marine community can then be examined with respect to mean temperatures, extreme temperatures and so on.
In addition to counting the abundance of marine invertebrates and algae, we will be tagging abalone, in an attempt to follow growth and mortality of individual abalone. We will also be measuring urchins which will allow us to follow changes in the population structure over time.

What will you need to know to sample these sites?
There are a number of plant and invertebrate species that you will need to be able to identify before we can sample the sites. You will also need to know how to sample using a quadrat, tag abalone and use vernier callipers… not exactly difficult stuff.
You will also need to know how to enter and analyze the data you collect. We will set things up so that this is straightforward. At the end of the school term you will be able to plot the mean abundance of the organisms we sample at all of our permanent transects. In subsequent years other Pearson College divers will continue to sample these sites.

Some species you will need to know
Phylum Echinodermata

Red urchin – Strongylocentrotus franciscanus
This is the most abundant of the urchins, it is unmistakable, being big and red. We will count the number of red urchins in each quadrat, as well as measuring the test diameter of the urchins. This will be done with vernier callipers. By measuring the size of the urchin tests we will be able to trace the settlement of new “recruits” and follow their growth.

Green urchin – S. droebachiensis
This is the smaller green urchin that is quite common in sheltered areas. We will count green urchins, but not measure them, unless they are very abundant at any of our sites.

Purple urchin – S. purpuratus
A small purple urchin that is generally found in the very shallow subtidal, and sometimes in the intertidal. If it occurs on any of our sites we will count them only.

Green urchins – S. droebachiensis
A small green urchin that is generally found in more sheltered waters, we will probably not encounter too many green urchins.

Giant sea cucumber – Parastichopus californicus
A large browny red sea cucumber, These are generally found in sheltered areas, or in water depths of greater than 10m. They are found on both hard and soft-bottoms.

Orange sea cucumber – Cucumaria miniata
This cucumber has a browny red body and bright orange tentacles. It is found in crevices wifli its tentacles extending beyond the crevice.

Sunflower star – Pycnopodia helianthoides
The largest of the sea stars, it can be up to lm in diameter, it comes in a variety of colours, usually orangy brown. It has up to 24 legs.

Leather star – Dermasterias imbricata
The leather star has a red back with greeny makings. It derives its name from its ieather-like texture. If you smell it (no not underwater) it has a gunpowder/garlic smell.

Beach star – Pisaster ochraceus
Yellow or purple, generally intertidal, but also found subtidally at some locations .

Painted star – Orthasterias khoeleri
Orange pink and purple, a very attractive sea star that occurs subtidally on rocky bottoms.

Blood star – Henticia spp.
This bright red, star is very common on both rocky and soft-bottomed areas.

Basket star – Gorganocephalus eucnemis
This species usually occurs in deep water, but Race Rocks is unique in having this species in shallow subtidal water.

Phylum Mollusca
Abalone Haliotois kamtschatkana
The pinto abalone occurs from the lower intertidal to depths of about 10m. We will count, measure and tag all of the abalone we encounter. When tagged abalone are re-encountered they will be re-measured to follow growth in abalone.

Red turban snail – Astraea gibbersoa
A medium-sized snail that is very common on coralline algae. It has a hard operculum, and a shell that becomes covered with coralline algae.

Gumboot chiton – Cryptochiton stelleri
‘Ite largest chiton on our coast. You cannot see the 8 shell or plates that make up the gumboot chiton’s shell, they are hidden beneath the pinky brown tissue on the dorsal surface.

Plumose anenome
Metridum senile
A very abundant bright white anenome, that does particularly well in high current areas. We will count anemones as we encounter them.

There will be other invertebrates added to this list once we determine which species are representative of the areas we are sampling.

Brown Algae
Kelps – Laminariales
brownalgaeBull kelp – Nereocystis luetkeana
Bull kelp is an annual species, it grows rapidly in areas that are highly disturbed. Bull kelp forms a floating canopy, it is very common at Race Rocks.

Tree kelpPtrerygophora californica
Tree kelp looks very much like a tree. It is a perennial species that lives in excess of 17 years. Pterygophora can be aged by cutting it down and counting the rings in its stalk or stipe. We will be tagging tree kelp on one of the transects at Race Rocks this will allow us to look at the persistence of tree kelp

Eisenia arborea
Eisenia looks
very much Pterygophora, except that it has blades which are serrated at the edges, and the blades grow in two “bunches” at the top of the plant.

Laminafia setcheIlii
Laminaria groenlandica
These two species do not have a common name. Laminaria setchellii found in similar areas to Pterygophora, except that Laminaria setchellii is generally found in slightly more exposed areas.
Laminaria groenlandica is found in more sheltered areas. It looks quite different than Laminaria setchellii, since the two species are found in different areas you should have no trouble sorting them out.

Costaria costata
Costaria is really distinctive, it has three ribs on one side and two ribs on the other. It is generally an annual species but frequently manages to overwinter.

Acid weed Desmarestia spp.
Acid weed is an annual species, which has a very “weedy” life history, it grows in highly disturbed areas, and is one of the first species to grow in areas that have been disturbed. It is very hard to count, because it forms a blanket over the sea floor, to count it you have to go down to the holdfast.

Pleurophycus gardneri
This species is generally found in very shallow areas in wave-washed areas. It is very distinctive.

There will be other species of algae that we add to our list.


To sample the invertebrates at each of the permanently marked sites we will be using quadrats. Most of you will have done quadrat sampling before.
We will be using a random – sampling method, in which quadrats are placed randomly along / or near the transect line, and the selected invertebrates and algae in each quadrat will be counted. From these data we will calculate the mean (average) abundance as well as the variation in abundance that occurs at each site. These data will plotted in graphs which compare the abundance of each species over time, and with respect to changes in temperature.
We will go over the sampling methods prior to starting the project. All data will be recorded on data sheets pre-printed on underwater paper. An example of the type of data sheet we will be using is attached.

Proceed to Sampling plan: