I Need a Title and I Need an Abstract Next Time

I need a title and I need an Abstract next time

Title= 0 pts

Introduction [0, 0, 2, 0, 2, 2, 4, 0, 4, 2, 2] 18 pts

An important goal in ecology is to understand the distribution and abundance of species within their communities. Knowledge of the spatial structure and composition of ecological communities provides a baseline for investigating the mechanisms sustaining that structure and helps construct a framework upon which to test and develop ecological theory. The kelp forests of the northeastern Pacific coasts comprise some of the most diverse and productive temperate marine ecosystems on earth (seeSteneck et al. 2002). They provide support for many species, including commercially important fisheries (Tegner and Dayton 2000). Understanding species distribution within kelp forests can better inform ecological theory concerning the overall functional patterns within the systems (e.g. Dayton 1971, Cowen et al. 1982) as well as provide background data for statistical models that act as important conservation and management tools (Guisan and Thuiller 2005). Here, we use a qualitative survey method [start new paragraph and first state WHY you are using qualitative survey. Here you need to lay out the questions being addressed in the study.] to estimate the distribution of 28 species comprising three major taxonomic groups (algae, fishes, invertebrates) along a permanent transect within a kelp forest at Hopkins Marine Station (HMS) in Pacific Grove, California. Qualitative methods provide a general overview of species distribution and allow for relative ease of surveying (Obermeyer 1998, Huebner 2007). In addition to distribution of the 28 species along the transect, we examine the relative merits of the qualitative approach. [other way around… we assess the method for producing patterns of distr and abundance.] Specifically, in order to assess overall effectiveness of the qualitative approach we will inspect potential variation among individual survey teams as well as abundance variation among species. Using this information, we will discuss the advantages of a qualitative approach as it may apply to surveying the distribution and abundance of particular species (i.e. which species or taxonomic groups may be more or less well suited for such an approach).

Methods [2, 2, 0, 0, 2, 0, 2, 0, 0, 0, 2, 0, 2, 2, 4, 0, 0] 18 pts

Our approach to determining… was to … [give general overiew of approach, then break into subheadings!

Study system

We used a qualitative survey method to assess abundance and distribution of 28 species among three major taxonomic groups: algae, invertebrates, and fishes (Table 1). Surveys were carried out using scuba at each of 14 meter marks (80-145m in 5m intervals) along a permanent transect line running north-south offshore of Hopkins Marine Station in Pacific Grove, CA.

Subheading with first question

Each dive team performed two 30m counting passes on either side of the transect: the “deep” side (eastward: out and back) and the “shallow” side (westward: out and back). During passes, abundance of each species was recorded according to the following qualitative scale: 1: absent, 2: rare, 3: present, 4: common, 5: abundant. Dive team members collected data individually and group data was pooled for statistical analysis. We computed a variance component analysis using a linear mixed effects model fitting abundance to depth, meter mark, buddy, and buddy nested within meter mark. These variance components were additionally split by major taxa (algae, invertebrates, fishes). We computed pooled mean abundance by species and relative difference between buddy pairs for each qualitative abundance level.

Results

Species abundance

Mean abundances of major taxa across the transect line were (mean ±SD) algae: 2.54 ± 1.42, fishes: 1.66 ± 0.98, and invertebrates: 2.07 ± 1.33. Although abundances were recorded as categorical values, they are reported here as numerical data to show variation in the recorded values. Among fishes, painted greenlings (Oxylebius pictus) were most abundant (1.91 ± 1.02) and black and yellow rockfish (Sebastes chrysomelas) were least abundant (1.27 ± 0.98). Among algae, Macrocystis pyrifera was most abundant (3.81 ± 0.72) and Phyllospadix spp. was least abundant (1.29 ± 0.68). Among invertebrates, the bat star (Patiria miniata) was most abundant (4.12 ± 0.97) and red sea urchins (Strongylocentrotus franciscanus) were least abundant (1.12 ± 0.42) (see Figure 1). Mean species abundances are reported in Table 2.

Variance component analysis

The greatest amount of variance within taxa was found among the algae (variance of pooled algal abundance: 2.02) and the least amount was found among the fishes (variance of pooled fish abundance: 0.96). Variance component analysis on overall abundance revealed the greatest degree of variance among meter marks (~42%), with buddy accounting for ~37% and depth accounting for ~21% (Figure 2). When decomposed by taxa, buddy effect still accounted for the second greatest or greatest amount of variance within invertebrates and algae, although it was diminished within the fishes (Figure 3).

Buddy pair differences

Buddy pairs differed most among invertebrates, specifically Balanophyllia elegans (showing the most variation in agreement), followed by algae, and appeared to differ most uniformly (and generally least) among fishes (Figure 4). When examining percent agreement between buddies on presence or absence of a species (Figure 5), we see the greatest amount of disagreement among algae and invertebrates, although all three categories show variation.

Discussion

Our qualitative survey of Hopkins Marine Station species abundances provides a general overview of the distribution of species within the kelp forest. As previously stated, this information is useful in testing ecological theories about mechanisms sustaining that distribution, such as species interaction (competition, predation, etc.) (Dayton 1971). The true value of this study, however, may lie not in providing useable data for further ecological research but rather act as a benchmark from which the qualitative approach may be assessed. Our results show clear differences in the variances accounted for by the various factors within the survey (Figure 2, Figure 3). That dive buddy factors accounted for a consistently large proportion of the data variance shows a weakness in this approach. Survey methods were not specifically defined for each pass: divers collected data independently and did not discuss the data collection before descending. Species assemblages within kelp forests commonly show distribution gradients over depth and among habitat type (Foster and Schiel 1985, Hallacher and Roberts 1985). The overall variance component analysis shows the majority of abundance variance explained by meter mark and buddy factors. The transect line at HMS crosses multiple habitat types, and although our study did not account for differences in habitat type, this has some possible influence on meter mark effects. Additionally, due to depth related differences in species assemblages, we may expect depth effect to be significant. However, the large proportional component of the buddy effect likely obscures any real variation due to depth or habitat type (as a function of meter mark). Buddy effect may have multiple sources: differences in experience identifying species, familiarity with the habitat, stress due to task loading while diving, etc. These factors may confound the reliability of data recording as well as the simple ability of a diver to find and recognize species. In addition, neither the qualitative scale (absent, rare, present, etc.) nor the survey area (apart from the line transect) was clearly defined prior to the dive. Individual divers performed their counts according to their own interpretations of the survey methods. This claim is supported by the relative disagreement between buddies (Figure 5), which is high (>20%) across many species (although interestingly the two species reported most abundant: Macrocystis pyrifera and Patiria miniata show the least degree of disagreement, perhaps due to their sessile and easily identifiable nature). Fishes show the least overall (and most uniformly distributed) relative percent difference between buddies compared to other taxa (Figure 4), suggesting that qualitative approaches may more accurate for fish counts than invertebrates or algae. Using this approach, divers were most able to determine presence or absence of a species (as shown by percent difference as a function of abundance level, Figure 6). Difference between dive buddies increased as the level of definition between levels decreased (e.g. “rare” vs “present”). Based upon the results of this study, the qualitative approach seems best suited to tracking presence or absence of species and abundance of easily identifiable species. With well-defined survey methods and trained divers, this approach may be useful for tracking general abundance of specific species groups over time. Specific counts are not needed for assessing change over time, so long as the previous state is known. Current assessments are compared to previous assessments and large-scale patterns emerge. Qualitative methods are not effective for assessing actual population sizes but general change and overall “health” indices may be gleaned. Previous workers have found that qualitative studies are more effective in assessing overall structure (species richness and broad distributional patterns) whereas quantitative methods better show local scale patterns such as density, biomass, and recruitment (Obermeyer 1998, Huebner 2007). Based upon our study, I suggest that a combination of the two methods will provide the most accurate assessment of species distribution and abundance within the kelp forest community.

References [3, 3] = 6 pts loose the all caps on the article titles.

Cowen, R. K., C. R. Agegian, and M. S. Foster. 1982. The maintenance of community structure in a central California giant kelp forest. Journal of Experimental Marine Biology and Ecology 64:189-201.

Dayton, P. K. 1971. COMPETITION, DISTURBANCE, AND COMMUNITY ORGANIZATION - PROVISION AND SUBSEQUENT UTILIZATION OF SPACE IN A ROCKY INTERTIDAL COMMUNITY. Ecological Monographs 41:351-&.

Foster, M. S. and D. R. Schiel. 1985. Ecology of giant kelp forests in California: a community profile. FWS/OBS-85(7.2); Other: ON: TI86900095 United StatesOther: ON: TI86900095Wed Feb 06 16:58:53 EST 2008NTIS, PC A08/MF A01.ERA-11-001329; EDB-85-176955English.

Guisan, A. and W. Thuiller. 2005. Predicting species distribution: offering more than simple habitat models. Ecology Letters 8:993-1009.

Hallacher, L. E. and D. A. Roberts. 1985. DIFFERENTIAL UTILIZATION OF SPACE AND FOOD BY THE INSHORE ROCKFISHES (SCORPAENIDAE, SEBASTES) OF CARMEL-BAY, CALIFORNIA. Environmental Biology of Fishes 12:91-110.

Huebner, C. D. 2007. Detection and monitoring of invasive exotic plants: A comparison of four sampling methods. Northeastern Naturalist 14:183-206.

Obermeyer, B. K. 1998. A Comparison of Quadrats Versus Timed Snorkel Searches for Assessing Freshwater Mussels. American Midland Naturalist 139:331-339.

Steneck, R. S., M. H. Graham, B. J. Bourque, D. Corbett, J. M. Erlandson, J. A. Estes, and M. J. Tegner. 2002. Kelp forest ecosystems: biodiversity, stability, resilience and future. Environmental Conservation 29:436-459.

Tegner, M. J. and P. K. Dayton. 2000. Ecosystem effects of fishing in kelp forest communities. ICES Journal of Marine Science: Journal du Conseil 57:579-589.

List of Tables

Table 1. Species assessed using qualitative survey at Hopkins Marine Station

Table 2. Mean abundance of surveyed species

List of Figures

Figure 1. Mean species abundance by taxa

Figure 2. Variance component analysis of overall abundance by buddy, depth, and meter mark

Figure 3. Variance component analysis by major taxa

Figure 4. Relative differences between buddy pairs (%) among species, based on rank (1-5).

Figure 5. Percent disagreement between buddies

Figure 6. Relative difference (%) between buddy pairs as a function of mean abundance of species