Brief description
This study investigated the temporal and spatial patterns of recruitment of epifaunal species at Portsea. Recruitment panels were immersed at depths of 1 - 2.2 metres for 10 months (25/10/1975 - 11/9/1976) and 24 months (16/11/1977 - 14/11/1979) and at depths of 3 - 3.8m for 18 months (11/9/1976 - 18/5/1978). Each panel was divided into four quadrats (9 x 9cm) and the number of larvae recruits in each quadrat was recorded every 2 months using a binocular microscope. The replicate number of quadrats sampled every 2 months varied between 1 and 30 replicates. The mean number of larval recruits per quadrat for each period was calculated for each species at each depth. An additional treatment ('complex substratum' treatment) was added to 2 panels for 2-month periods from 13/10/1976 to 12/10/1977 to assess the effects of substratum complexity on the recruitment of epifauna. The complex substratum treatment simulated the physical structure of a barnacle and arborescent bryozoan community. On each panel there was 1 quadrat that was a complex substratum treatment and 1 quadrat that was randomly chosen from the 3 remaining to be analysed as the control. Thus, there were 2 replicate quadrats of each treatment (complex substratum and control) per 2-month period. At the completion of each period all individuals and colonies of each species were counted in each quadrat. Availability and abundance of settling larvae varied seasonally and annually. Rates of recruitment of larvae were greatest during spring, summer and autumn. Polychaetes, barnacles, hydroids, tubicolous amphipods and bryozoans recruited in greater abundance and more consistently throughout each year than did ascidians or sponges. A greater diversity of species settled on the complex substratum treatments and the density of settlement of some species was also higher.Lineage
Statement: COMPLEX SUBSTRATUM TREATMENT: Conical projections that were 6 mm in height with a 6 mm square base, which is similar in size and shape of the common barnacle (Elminius modestus), were made from the same material as the panels. Forty-nine of these 'artificial barnacles' were separated by 6 mm and attached to each quadrat (9 x 9 cm) on the panels in a chequer-board arrangement. The structure of arborescent bryozoans were simulated using pieces of 12.5 mm mesh nylon fish net formed into tufted, branching 'colonies' of similar size to the 2 most common bryozoans (Bugula dentata and Tricelleria porteri). The artificial colonies were about 3.5 cm in height and 5 colonies were attached to each of the quadrats between the artificial barnacles. The combination of artificial barnacles and bryozoans made up the complex substratum treatment. A flat 9 x 9 cm quadrat was used as a control for the complex stubstrata. PANEL SAMPLING: To reduce edge effects the panel surface within 6 cm of each end and 1 cm of each side of a panel was not analysed. The remaining 18 x 18 cm area was divided into four 9 x 9 cm quadrats, and 2 of these were chosen at random from each panel. All individuals and colonies of each species were counted in each of the 2 quadrats using a binocular microscope.Notes
CreditMartin, A.A., Dr
Purpose
(1) To determine the variability over time in the number of species of recruits and the abundance of recruits of epifaunal species within and between years. (2) To determine the effect of depth upon the number of species of epifaunal recruits and the abundances of recruits of epifaunal species. (3) To determine the effect of a physically complex substratum on the number of species of epifaunal recruits and the abundances of recruits of epifaunal species.
(1) To determine the variability over time in the number of species of recruits and the abundance of recruits of epifaunal species within and between years. (2) To determine the effect of depth upon the number of species of epifaunal recruits and the abundances of recruits of epifaunal species. (3) To determine the effect of a physically complex substratum on the number of species of epifaunal recruits and the abundances of recruits of epifaunal species.
Issued: 25 02 1981
Data time period: 1975-10-25 to 1979-11-14
text: westlimit=144.727; southlimit=-38.327; eastlimit=144.727; northlimit=-38.327
text: uplimit=3.8; downlimit=1
Subjects
10 000000 |
11 000000 |
20 000000 |
22 000000 |
27 500000 |
28 401000 |
35 000000 |
37 465002 |
ANIMALS/VERTEBRATES |
Ascidiacea |
BIOLOGICAL CLASSIFICATION |
BIOSPHERE |
Biosphere | Aquatic Habitat | Benthic Habitat | artifical substrata | pier piling |
Biosphere | Aquatic Habitat | Benthic Habitat | rocky substrata |
Biosphere | Ecological Dynamics | Competition |
Biosphere | Ecological Dynamics | Predation |
Biosphere | Ecological Dynamics | Succession |
Biosphere | Zoology | Invertebrates |
Bryozoa |
COMMUNITY DYNAMICS |
Community Structure |
Cirripedia |
EARTH SCIENCE |
ECOLOGICAL DYNAMICS |
Fish |
Hydrozoa |
Oceans | Marine Biology | Marine Invertebrates | epifauna |
Penicipelta vittiger |
Phyoxocephalidae |
Polychaeta |
Porifera |
Port Phillip Bay |
Portsea Pier |
Species Recruitment |
biota |
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Other Information
global : 9a56cc90-e354-11dc-97b4-00188b4c0af8
Identifiers
- global : e7571990-e3f5-11dc-856d-00188b4c0af8
