BACKGROUND
Quarry Cove at Yaquina Head Outstanding Natural Area, on the
central Oregon coast, is one of the first wheelchair accessible,
and human-constructed tidepools in the world. The design, to
maximize visitor enjoyment of the intertidal wilderness, while
at the same time minimizing impacts on the marine life, came
in part from studies carried out by Dr. Brosnan, Lana Crumrine
and Tim Grubba (SEI), and implemented by Mr. Steve Gobat (BLM)
the manager of Yaquina Head. Quarry Cove was opened to the sea
in 1994 and this presented an entire new bay for primary colonization.
This study documents the colonization of new marine flora and
fauna in the cove.
SEI studies at YHONA are continuing, contact
us for further information. SEI thanks the Bureau of Land
Management for support, Mr. Steve Gobat, manager of Yaquina Head
Outstanding natural Area, and Mr. Michael Noack.
Abstract
Quarry Cove at Yaquina Head, a human constructed series of tidepools
was opened to the sea on June 1, 1994. This study documents the
colonization on the rocks, both natural and gunnite (artificial
rock), of this new bay through the first year. As predicted,
barnacles were among the first species to colonize, and were
equally common on both types of rock. However, one species, Balanus
was more abundant on vertical surfaces than horizontal. Algal
species varied in abundance, for example, Ulva arrived
later than expected, while Analipus colonized rapidly.
Quarry Cove is a unique opportunity to study the successional
process in a large bay.
History:
The Yaquina Head Outstanding Natural Area (YHONA) encompasses
a one hundred acre headland on the Oregon coast, 1.5 km north
of Newport (Gobat 1995). Human use of the headland has been documented
back to 5,000 BC, when Native North American's occupied the headland
(Gobat 1995). With the arrival of settler's in the 1800's, came
the exploitation of the headland's resources such as agriculture,
timber, and rock (Gobat 1995). These exploitations severely impacted
the headland, leaving it dehabilitated. Today, the headland is
used as a light house site and managed as an area for conservation,
rehabilitation, recreation and education.
The Bureau of Land Management (BLM) was given the responsibility
of implementing these laws through 1) the conservation and development
of the scenic, natural, and historic values of the area; 2) the
continued use of the area for purposes of education, scientific
study and public recreation which do not substantially impair
the purposes for which the area is established. and 3) protection
of the wildlife of the area. The BLM places an equal effort on
all three responsibilities (Gobat 1995).
Existing Intertidal Areas:
At the present time, there is one natural intertidal area open
to the public at Yaquina Head. This area is classified as a Marine
Garden that receives the most visitors at roughly 65,000 per
year compared to the other three marine gardens in Oregon (Gobat
1995). This level and intensity of visitation has had an extremely
negative impact (mainly trampling) on the intertidal communities.
This impact was well documented in a series of studies conducted
on the Oregon coast at Yaquina Head and other locations by Dr.
Deborah Brosnan, and Lana Crumrine (Brosnan and Crumrine 1994,
1995) and continued by Dr. Brosnan and Timothy Grubba. As a direct
result of these studies, the BLM developed new management practices
to minimize human impact.
Quarry Cove Intertidal Area:
The Quarry Cove intertidal area was designed and constructed
to satisfy both the requirements of intertidal communities and
those of the visitor. This makes this intertidal area unique,
as there will be less of a negative interaction between the organisms
present and the visitor. The design incorporates a number of
control mechanisms, such as a path system, that limits but directs
the visitor through the area with maximum exposure to the intertidal
experience and minimal impact to organisms. This frame work allows
the new intertidal area to be used as a powerful tool for recreational,
conservation, and educational activities.
Colonization at Quarry Cove:
Quarry Cove was not open to the sea during the initial phase
of construction, but after the completion of construction on
the quarry floor on June 1, 1995, it was opened to the sea. Upon
its' opening the cove became a very unique area, unique in the
fact that such a large area of bare intertidal was open to colonization
(Brosnan and Yamada '94). The only instances where this usually
occurs is after some large scale natural phenomenon, such as
an earthquake or volcanic activity (Brosnan and Yamada '94).
It also offered a unique opportunity to study succession and
development of an intertidal area. The first monitoring program
was initiated on June 8, 1994 and concluded on August 22, 1994
and was incorporated into the report by Brosnan and Yamada 1994.
A list of the species that arrived during this monitoring period
are listed in table 1. BLM continued to document the colonization
of species after the initial monitoring program. This study began
in November, 1994 and concluded on July 30,1995 and is the first
study at Quarry Cove that has focused on colonization on a small
scale.
Colonization: rate and sequence.
There are two aspects of colonization/succession that must be
considered: 1) rate; and 2) sequence. The rate and sequence of
colonization/succession are determined by numerous factors and
their combinations. Factors can include: 1) the type of succession
i.e. facilitation, inhibition or tolerance.; 2) dispersal characteristics
and presence of a species.; 3) biotic conditions i.e. other species.;
and 4) abiotic conditions i.e. substrate. The variability of
these factors make the prediction of rate and sequence difficult
or impossible. However, general predictions can be made by comparing
the rate and sequences of similar communities that have been
studied.
A typical colonization/successional sequence that occurs on the
Oregon coast includes (Farrell 1991; Grubba and Brosnan 1993):
1) Diatoms
2) Early successional algae e.g. Ulva sp.
3) Sessile organisms e.g. barnacles
4) Mid successional algae e.g. Gigartina
5) Late successional algae e.g. Fucus distichus
6) Late successional species e.g.
mussels
The successional sequence for Quarry cove for the first three
months was predicted by Yamada in Lee, et al 1993. They made
the following prediction based on other studies:
1) Colonial diatoms (Fragelaria sp.);
2) Ephemeral thin bladed algae
(Enteromorpha sp.) and
3) barnacles (Balanus glandula).
The actual observed colonization/ successional sequence over
the first three months followed this prediction. However there
were many other species present.
