viernes, 11 de agosto de 2023

Coral algae cover - Fish Pond Monitoring Project FP 2023

Authors: Erick Morales Oyola, Rudy Paddock, Daniel Hirata, and Ezra Bergson-Michelson.

In this survey, we observed the cover of algae both inside and outside of a reconstructed fish pond in Pā’ea, Tahiti, French Polynesia. Fish ponds, as you all know, were traditionally used by the Polynesians as a form of aquaculture. The rock barriers were used to trap adult fish within the fish pond, providing a regular supply of fish when ocean fishing was not possible. Through this survey, we hoped to further understand the ecology of the fish pond, focusing on how the microhabitat created within the rock walls would affect the marine life that the fish pond was supposed to attract. In this survey, the proposed research question was whether or not there was a difference in algae cover and genus abundance inside versus outside the fish ponds.

We began by measuring the total area of the fish pond, which was found to be 15 meters by 15 meters. Then, we divided each length into quarters, with markings at 0, 5, 10, and 15 meters. The 0 and 15 meter marks include the area of sand directly adjacent to the rock walls of the fish pond. We laid one transect along the shoreline, labeling it as our x-axis. We laid another transect perpendicular to the shore along the fish pond wall, labeling it the y-axis. Due to limited transect availability, the x-axis points were marked with rocks for reference while in the water. Then, the bottom right corner of the quadrat was laid at each point of intersection. For example, a quadrat was laid at (0,0), then (0,5), (0,10), and (0,15). In each quadrant we estimated the total percent coverage of all algae and recorded the incidence of different algal genus’. The same process was repeated for a 15x15m square that was 15m north away from the fishpond. It was in at the same position out from the shore.

Our findings were not statistically significant, given that we obtained a P-value of 0.7413. Within the fish pond, there was a 28.00% mean coverage, whereas the control site had a mean algal coverage of 25.13%. The standard deviations for algal coverage for the fish pond and control sites were 26.14 and 22.54, respectively. Our 95% confidence gave us intervals of 28.00+/-12.808 and 25.13+/-11.044 for the fish pond and control sites. Further, the observed instance rates of genus Turbinaria, encrusting algae, genus Halameda, and the ”Other” category were higher in the fish pond. On the other hand, brown turf algae, genus Padina, and genus Sargassum were more common in the control site. Additionally, on the rock walls of the fish pond, brown turf algae was the most common algae found. There were small sporadic patches of various other algae types, including genus Halameda and encrusting algae in addition to branching and encrusting coral. The Shannon diversity index using quadrat instances for algae genuses gives the fish pond site an index of 1.55. The species evenness was found to be 0.866 with a species richness of 6. The total number of individuals was 35, and the average population size was 5.83. The Shannon diversity index for the control site was also 1.55 with a species evenness of 0.863 and a species richness of 6. The total number of individuals was 31 with an average population size of 5.17.

As our results were not statistically significant, we found there was no significant difference between the algal coverage between the fish pond and control sites. However, there were varying trends within each site. In both sites, algal coverage increased with depth. However, in the fish pond site, the underlying substrate was a significant factor in addition to the evident trend of depth and algal coverage. In the fish pond, genus Halimeda and genus Turbinaria were only present on rocky substrates in addition to being more common at deeper depths. Outside of the fish pond at the control site, genus Turbinaria and genus Padina were prevalent at deeper depths, with encrusting algaes being much less common. Turf algae was also less common outside of the fish pond. These observations led us to believe that the fish pond is accurately simulating the natural algal cover of the coastal ecosystems in Pā’ea. However, with only one control site, randomness in choosing the location of this site may have been a factor.

There are a few potential sources of error:

A small sampling size in terms of number of sites.
Proximity of the second site to the fish pond.

Potential areas for improvement:

More sites spread out over a greater area and variety of substrate types.
More sampling sites within the fish pond.

In conclusion, we found no statistical difference between the algae coverage inside and outside the fish pond. Nonetheless, more research could be conducted to understand more about the microhabitats found within fish ponds.

Publicado el viernes, 11 de agosto de 2023 a las 04:23 AM por langzi langzi | 0 comentarios | Deja un comentario

viernes, 04 de agosto de 2023

Fish Biodiversity and Behavior Patterns- Fish Pond Monitoring Project FP 2023

The objective of our fish pond monitoring project was to collect data on the behavior and biodiversity of fish families that are found inside the pond, near the pond. as well as in outer regions of the reef. Since the topic and goal for the monitoring project was already given by the previous group, we altered their methods to increase accuracy and precision of the study.

Our methods changed slightly from the past years. To conduct our experiment we measured 3 sites: the inner fish pond, the exterior of the fish pond, and the outer coral reefs. We used transects to collect our data and had two researchers hold the transects at 15m of length while the other 2 researchers swam on either side of the transect, observing the area below them that went 1m out from the line (therefore 30m^2). Three of these transects were taken per site. The recorders swimming noted different fish species, amount of fish per species, as well as the behavior the fish performed when first spotted on the recorder’s swim. Each transect swim took about 3 mins.
To place the transects in the inner pond when facing the water, one transect was along the left wall, one along the right wall, and one at the centerline of the fish pond, also perpendicular to the shore.
The transect of the outer pond simply lined the outer section on the pond going 2m beyond the fish pond structure along the left, back, and right wall.
The outer coral reef collection site was at 328, 05 according to Tomas’ camera determined by a buoy placement that was swam out through the use of a scuba jet. The buoy was placed at approximately 17° 42' 27" South 149° 35' 11" West. Three transect lines were placed perpendicular to the shore mimicking the inner pond formation (each line being 6.5m apart with the center line starting directly on the buoy).

To analyze our data we compared behaviors in the different sites through percentage breakdown and also used a Shannon’s index to find differences in fish species diversity.

Compared to last year (what changes and why)
-Using transects to swim across to count fish and observe their behavior instead of a 20 minute floating survey of a given area to avoid fish recount and for unbiased collection
-The location of observations that were analyzed outside of the fish pond because we wanted to have a better scope of the area between the shore and the wave breaks. Going to the farther reef was also requested since the fish pond ecosystem is supposed to mirror that of a reefs
-The use of statistical analysis to support any anecdotal observation (ie Shannon’s index and percentage comparisons) because beforehand there wasn’t much data we could go off of and compare to, just general observations. Data collection provides a concrete comparison for people who will replicate the experiment in the future


General fish spread
We saw mostly damselfish, wrasse, and Butterfly fish. In both the outer and inner pond damselfish were the dominant family while wrasse was the majority in the outer reef with damselfish second. We saw a wider variety of fish families in the outer reef where we saw 11 families compared to the inner and outer pond which had 7 and 5 families respectively.

Shannon’s index
The calculated Shannon's index in the outer reef was 1.63, 1.26 in the outer pond, and 1.19 in the inner pond. This supports the fact that diversity was highest in the outer reef compared to the inner pond.

Fish per square meter
In the outer reef, we found 2.23 fish per square meter, outside the fish pond there were 1.104 fish per square meter, and inside the pond there was less than 1 fish per square meter. This information shows that the outer reef also had higher abundance than the other two sample sites.

Behaviors in each area: Top percentages of each behavior

Lagoon- 44.3% were freely swimming, 19.9% were territorial, and 16.4% were eating coral

Outer pond- 41% were freely swimming, 25.6% were territorial, and 12.8% escaped

Inner pond- 47.2% were territorial, 33% were freely swimming, and 10.4% were eating algae

Which behaviors were done by fish families: Top percentages

Territorial fish - 100% were damselfish
Swimming fish - 58.4% were wrasse and 20.2% were damsel
Coral eaters - 81.8% was an unidentified fish that we think is a juvenile parrot fish

Outer pond:
Swimming fish - 40% were damsel, 28.6% were goat fish
Territorial - 92% were damsel, 6% were soldier
Escaped, 90% were damsel, 10% were butterfly

Inside pond:
Territorial - 100% were damsel fish
Swimming - 56.2% were damsels
Algae eaters - 100% were wrasse


Overall, our group found that there was a higher diversity in the outer reef than the inner pond as well as the two meter perimeter surrounding the pond, which was also observed by last years group.This is reflected by our Shannon’s index values, where the outer reef value was greater by 0.44. Additionally, we observed a higher abundance of fish in the outer reef, which is seen in our data concerning fish per square meter, where the outer reef had about 4.5 times more fish per square meter than the inner pond.

We hypothesize that biodiversity is greater in the outer reef because there’s a significant difference in coral abundance, which acts as a resource for food and habitat. Next, we saw the the most predominant behavior was freely swimming except for in the pond where the top behavior was territorial. Territorial was the next most common behavior in the other areas as well. Damsel fish were most predominant in the territorial behavior category. A notable thing we noticed was that there was a high amount of damsel fish inside the pond made up of Gregory and the banded sergeant. We saw a disproportionately large amount of territorial behavior inside the pond compared to outside the pond where we sampled more wall space which tended to host territorial behavior.

We hypothesize that higher territorial behaviors in the pond could be related to the size of the pond. The smaller space may cause competition for resources and habitat.

Our biggest take awaysys were that damsel fish were a dominant family inside of the pond leading to high levels of territorial behaviors. This is a similar finding as last years group. Additionally, we noticed a higher percent of damsel fish inside the pond compared to outside the pond and the outer reef also similar to last years group.

Publicado el viernes, 04 de agosto de 2023 a las 12:51 AM por langzi langzi | 1 comentario | Deja un comentario

Paea Lagoon Aua i'a Fish Pond Monitoring, Group 3: Benthic Cover, Tahiti, FP, 2023

Bella Suhr, Olivia Berman, Bailey Wallace, Lucy Baker
Wildlands French Polynesia 2023

Fish Pond Substrate Composition Survey
(Click the link for figure and data tables)


We began this experimental survey as a follow-up to the Wildlands 2022 French Polynesia group whom conducted a substrate composition survey of a locally owned traditional fish pond in Taverea, Tahiti, on the Western side of the island. The owner of the fish pond requested insight regarding the main composition and type of substrate cover occurring in his pond. The previous research indicated the highest composition to be sand at 49.4%, then microalgae at 27.3%. This previous study had a sampling universe that included the pond and a 1-meter buffer around the pond's rock barrier and used randomly selected sample sites. This resulted in placing the inside and outside of the fish pond in one data set rather than separate resulting values that would allow for the comparison of the two. This previous survey provided a good basis for our prospective substrate composition but after further discussion with the owner of the pond. We decided to complete a new survey to observe any differences between the substrate within the fish pond, the region left of the fish pond, and the right of the fish pond. These are observed looking at the fish pond from the shore. This is due to the fact that a channel in the lagoon causes the current to flow South to North, or left to right when looking at the fish pond from the shore. This means the water flows through the left side, then through the rock barrier of the pond, and out to the right side. This produced our research question; If the fish pond is acting as a barrier or filter for the South to North current in the lagoon, what effect does the fish pond have on the substrate composition along the shore? To investigate this we decided to formulate our own methods that allowed us to compare the fish pond substrate composition to its surrounding areas.


We began by taking measurements with a tape measure of the inner wall of the fish pond and found it to be 14.1x13 m (width x depth). The image above demonstrates our sampling universe, with the black square representing the fish pond, the red square showing our sample area to the left of the pond, and the green square showing our sample area to the right of the fish pond. Using 2 transects we laid out a 14.1x13m grid in each of our three locations. We determined the x-axis to be 14.1 m (horizontal to the beach) and the y-axis to be 13 m (vertical to the beach). With a random number generator, we determined 10 random coordinates on the x-axis and y-axis for each location, thus adding up to a total of 30 coordinates for the whole sampling universe. The bottom left corner of each box was deemed the (0,0) coordinate and a grid was formed. At each coordinate we used a 1 meter by 1 meter quadrat to assess the percent coverage on the grid, only considering the uppermost primary substrate layer. We classified the substrate by alive coral, sand, dead coral, rock, microalgae, and macroalgae. For this study, we considered microalgae to encompass algae less than 1cm and macroalgae to be larger than 1cm. One person held the quadrat down in place, another person recorded the values, and the final two people acted as observers of the substrate type. The two observers would look into the water with snorkel masks and estimate the percent of each substrate within the quadrat. The two agreed on the percentages for each sample quadrat and reported them to the recorder. When assessing percent coverage we did not go over 100%, we recorded only the topmost layer of the substrate. The values were recorded on waterproof slates and this sampling method was repeated for each of the 30 random coordinates, keeping the data for each of the left, fish pond, and right areas separate from each other.


The data collected throughout our study is represented in the tables in the Google doc linked above.


Upon comparing the mean substrate coverages with independent sample t-tests between the left and fishpond, fishpond and right, and left and right sample areas for each substrate category, we found that there is no statistically significant difference in mean substrate coverage in all 3 sample universes.

In regards to our research question (if the fish pond is acting as a barrier or filter for the South to North current in the lagoon, what effect does the fish pond have on the substrate composition along the shore?), our results suggest that the fish pond has a negligible impact on the substrate coverage on the area immediately surrounding the fish pond.

This could indicate that, in terms of substrate, the fish pond is not significantly altering the substrate coverage directly surrounding the fish pond thus the substrate environment is similar inside the fish pond as it is directly to the right and left of it.

When comparing this year's data to last year's, we did notice that the substrate coverage of sand has increased (2022 - 49% sand, 2023 - 77% sand inside the fish pond. We are not able to determine statistical significance between these averages due to the differences in the sampling universe, but it is a noticeable difference that could be due to various factors. One factor could be that last year's sample universe included the rock barrier of the fish pond itself. Another factor could be that the sand substrate coverage did actually increase, but we cannot determine that for sure with the data we collected.

As an anecdotal observation, we did notice that the particle size of the sand varied between the three sample sights and in smaller microhabitats. We did not have the instruments, resources, or time to properly investigate this observation.

In a future study, a possible endeavor could be the investigation and analysis of the substrate depth and its relation to the size of sand particles. As the current could be pushing sediment through the fish pond and acting as a sieve that only allows smaller particles to pass through. Meaning a build-up of sand could be occurring and the substrate could be affected in that way rather than a substrate coverage alteration.

Therefore there is room for more investigation of the substrate within and around the fish pond and we look forward to future results. Thank you.

Publicado el viernes, 04 de agosto de 2023 a las 12:31 AM por langzi langzi | 0 comentarios | Deja un comentario

jueves, 03 de agosto de 2023

Paea Lagoon Aua i'a Fish Pond Monitoring, Group 1: Invertebrate Abundance, Tahiti, FP, 2023

Paea Lagoon Aua i’a Fish Pond Monitoring, Group 1: Invertebrate Abundance, Tahiti, French Polynesia, 2023

Authors: Kylee Dungan, Bianca Berron, Bridgette Castelino, Roo Swain


August 2, 2023
11AM - 2:32PM
Beaufort 0
Cloud 7% cover

Invertebrate Survey Methods:

We split our area into three main categories: the fish pond, boulder substrate to the South of the fish pond , and sandy substrate to the north. Within each of these categories we took two 12 meter long transects perpendicular to the shore 4 meters apart from each other. Two surveyors swam along each side of the transect, recording the number of invertebrates within one meter on either side for a total of 2 meters of observation. The invertebrate families we looked for included snails, hermit crabs, sea cucumber, worms, urchins, crabs, clams, shrimp, and sea stars; specifically crown of thorns sea stars due to the occurring outbreak. The data from both surveyors were combined in the end to find the totals of each family per transect.

Additionally, for the fish pond, we separated it into three categories: the interior floor, the interior wall, and the exterior wall. The entire fish pond is 14 by 13 meters not including the walls. For the interior floor, we placed our transects 5 meters from the right side (north) of the interior rock wall facing the ocean for the first, and 9 meters from the same boundary for the second transect. For each side of the wall, we counted the number of invertebrates on and within a meter. This was done the same way as the transects but with only one person swimming and recording along each side of the wall.

Notable Changes From Last Year:

There were two major changes that were made from the surveys last year. Rather than counting the total number of invertebrates as a whole, we tallied the number of individuals found in each family. This gave us an idea of which invertebrates were most abundant, which were the worms and urchins. Another major change we made was sampling both inside and outside of the fish pond. We kept the transect lengths the same and surveyed the walls according to least years methods, but only took two transects rather than six inside of the pond. Per Tomas’s request, we added an extra two transects on either side of the pond, one about 75 meters to the South with rocky substrate and one about 120 meters to the North with sandy substrate. this helped us gauge the effects of current and substrate on invertebrates.
Using the same methods to survey the interior and exterior wall, we found a 155% increase in abundance on the interior and a 34% increase on the exterior of the wall from last year's data.



To determine whether invertebrate abundance and diversity differed between sites, Shannon’s indices were calculated. In order from lowest to highest, Shannon’s index for the sandy substrate was 0, 1.194 for the interior floor, 1.307 for the rocky substrate, and 1.501 for the fish pond wall. Next, a total of 9 t-tests were conducted. Out of these tests, 3 were statistically significant. The amount of invertebrates found in the fish pond interior floor differed significantly from the sandy substrate with a p-value of 0.036. The amount of invertebrates found in the fish pond interior floor also differed significantly from the fish pond wall with a p-value of 0.016. Lastly, the amount of invertebrates found in the rocky substrate differed significantly to the sandy substrate with a p-value of 0.027.

In contrast, the following comparisons were not significantly different: the amount of invertebrates in the fish pond interior floor to the rocky substrate, fish pond wall to the rocky substrate, left fish pond wall to right fish pond wall, exterior left fish pond wall to exterior right fish pond wall, exterior left fish pond wall to interior left fish pond wall, and exterior left fish pond wall to fish pond interior floor. These tests were performed to determine the effect of current on invertebrate abundance since the current was flowing approximately from south to north, or from left to right when looking at the ocean from shore.

Despite the current Crown of Thorns outbreak, we did not observe any individuals in or around the area.


Our client was interested to see the differences in invertebrate population covers across different substrates and various locations along the Paea coastline of Tahiti, especially those differences caused by changes in current flow and the presence of the sheltering fish pond structures.

The several t-tests performed suggest that the effect of substrate is greater than the effect of current on invertebrate presence and diversity. Significant differences were found between boulder and sandy substrates, and no statistical difference was found between sheltered and unsheltered areas.

Shannon’s index also confirms that diversity increases with rocky substrate, something we expected due to the porous nature of the basalt rock that invertebrate species like to take advantage of.

An observation that I would like to point out is the presence of worm tubes in the sandy area. Other than the singular snail found at the northern sample site, there were numerous worm tubes hidden beneath the sand. I thought this was an observation important to notice, as it is an example of a species making use of a relatively barren environment. It may even be an example of a pioneer species beginning the rebuilding of a reef, but more research would need to be done to confirm.

We’d also like to mention how although we could not turn every stone to find every small snail and hermit crab, our methods were fairly thorough given the time and resources. We’d like to thank you for sharing your home and allowing us to learn from the beautiful environment here. Thank you for listening and we hope that our findings can contribute to your work in some way.

Publicado el jueves, 03 de agosto de 2023 a las 11:00 PM por langzi langzi | 0 comentarios | Deja un comentario

sábado, 06 de agosto de 2022

Paea Lagoon Aua i'a Fish Pond Monitoring, Group 3: Benthic Cover, Tahiti, FP, 2022

Substrate cover of the fish pond was measured using a 1 square meter quadrat for 20 preferentially sampled areas within the fish pond and 1 meter surrounding the outside perimeter of the fish pond walls. 20 total quadrats were taken within this sampling universe. Quadrat placement was measured on a grid of the fish pond, where we measured the quadrat distance from the southern most corner of the rock fish pond closest to the house wall (AKA the bottom left corner of the fish pond). However, for calculating quadrat distance considering the 1 meter extension of our sampling universe beyond the rock wall, we measured 1 meter south from the southern corner part to match the end of our sampling universe. We considered this spot the "origin" or starting point of all measurements at 0 meters in width and height. Quadrat placement was measured on the grid for replicability of future groups including 20 preferentially chosen placements. Substrate cover categories included coral, sand, coral rock, river rock, turf algae, and macro algae. The mean and standard deviation was calculated for each substrate category.

The quadrat locations are as follows including formatting of (Height, Width) in meters from the starting point of (0,0). These measurements are to the bottom left corner of the quadrat. Coordinates of our quadrats were: (5, 4.6), (7.5, 8.7), (13.3, 6.1), (10.8, 15.2), (14.1, 15.4), (9.2, 12.1), (2.8, 2.5), (5.5, 11.4), (8.1, 17.9), (15.6, 14.1), (4.4, 6.1), (7.2, 5.3), (9.7, 6.9), (14.4, 6.2), (13.8, 1), (7.1, 1.1), (12.5, 19), (11.3, 15.2), (5.6, 8.9), (3.1, 12.4)

For each quadrat two surveyors estimated the percent coverage for each quadrat peramater. The parameters evaluated were coral, sand, coral rock,river rock, turf algae, and macro algae cover. After field data collection, we calcuated the average percentages of each substrate between the two individual observations of the same quadrat to eliminate bias. Using these 20 average points for each type of substrate (coral, sand, coral rock, river rock, turf algae, and macro algae) we calculated the mean and standard deviation (S.D.) for each substrate as shared below.

Coral: Mean = 10.125% and S.D. = 0.26
Sand: Mean = 49.425% and S.D. = 0.27
Coral Rock: Mean = 1.25% and S.D. = .028
River Rock: Mean = 16.35% and S.D. = 0.16
Turf Algae: Mean = 27.25% and S.D.= 0.20
Macro Algae: Mean = 1.8% and S.D. = 0.14

Based on these percentages the greatest to least percentages of substrate cover within the pond and 1 meter on the outside perimeter of the pond was sand, turf algae, river rock, coral, macro algae, and coral rock.

Publicado el sábado, 06 de agosto de 2022 a las 01:09 AM por langzi langzi | 0 comentarios | Deja un comentario

Paea Lagoon Aua i'a Fish Pond Monitoring, Group 2: Fish Biodiversity and Behavior Patterns, Tahiti, FP, 2022


For this project, we separated the fish pond into three sections; the interior of the pond, a four-meter buffer area surrounding the exterior wall, and further out into the lagoon. We split the interior pond and exterior perimeter into three sections, one for each person to observe, and for 20 minutes in each section we floated around and observed the behavior and relative abundance of 22 fish families that are frequently observed at and around the pond. To do this, we tallied how many fish of each family we saw and organized their behavior into 10 behavioral categories (A- feeding on algae, B- feeding on the substrate, C-feeding on coral, D- hiding in rocks, E- juvenile fish taking refuge, F- freely swimming with no distinguishable pattern, G- other behavior and provide comments, H-hunting, and T- protecting their territories). When we observed the outer lagoon, we focused on examining behaviors that we did not see in the pond rather than counting for fish individuals.

Our results revealed some of the more common behavioral patterns observed inside and on the exterior of the wall:

  • Damselfishes were the most abundant family noted and were almost always found hiding inside of the wall rocks on the inside and outside of the pond. They exhibited typical territorial behavior and often chased other fish families away. Outside in the outer lagoon, we did not see a high abundance of damselfish due to the large amount of macroalgae, showing that the ponds provide an ideal habitat for this family.
  • In the inner and outer perimeter of the fish pond we observed juveniles from surgeonfish, butterflyfish, and triggerfish families. They were concentrated in smaller rocks that were not a part of the rock wall. None were sighted beyond the four-meter buffer zone, highlighting that the fish pond may serve as a nursery for a variety of families. In order to better facilitate the fish pond as a nursery, we suggest increasing the amount of smaller rocks within the center of the pond to provide this preferred habitat.
  • As a general pattern, we primarily observed families feeding on the benthic substrate, rather than coral or algae. We noted a lower density of herbivores than we have seen on other reefs. For example, we counted no rabbitfish and a lower abundance of surgeonfish.
  • We observed snappers and prey fish hiding in the rocks, which might indicate that the fish pond walls serve as a refuge for these fish.
Publicado el sábado, 06 de agosto de 2022 a las 12:47 AM por langzi langzi | 0 comentarios | Deja un comentario

Paea Lagoon Aua i'a Fish Pond Monitoring, Group 1: Invertebrate Abundance, Tahiti, FP, 2022

To survey invertebrates in the fish pond, we divided the area into three sections: the interior wall, interior floor, and exterior wall. We recorded every invertebrate species we observed, grouping them by families.

To measure abundance on the interior wall, 3 surveyors swam within a meter inward from the base of the wall, recording number of individuals seen on and around the wall.

To measure abundance in the interior of the pond, we laid transects every two meters starting from the southeast end, conducting swath surveys. We avoided the area a meter from the interior wall. Each of six total swaths was two meters wide and 14 meters long. Two team members held two transect tapes to mark the area of the swath while the other team member swam up and down the swath area counting each individual invertebrate.

To survey the exterior wall our team of 3 swam along the entirety of the outside of the wall and counted invertebrates on the rocks, then turned around and counted invertebrates on the sand extending two meters from the wall on the way back.

Additionally, we used a ScubaJet to count Crown of Thorns Starfish across three transects extending west about 25 meters from the outer edge of the pond, one on either corner and one in the middle.

Families we observed were snails, hermit crabs, crabs, urchins, sea cucumbers, worms, shrimp, and sea stars. We also recorded holes and mounds that indicated the presence of invertebrates.

Interior Floor:

  • 38 individuals counted
  • Average transect had 6.3 invertebrates (with a standard deviation of 1.82)

Interior Perimeter:

  • Average of all surveyor's data was 38 invertebrates (with a standard deviation of 2.42)
  • Most abundant species was worms, with an average between observers of 17 individuals

Exterior Perimeter:

  • Average of all surveyor's data was 58 invertebrates (with a standard deviation of 14.63)
  • Most abundant species was hermit crabs, with the average among observers 10. This excludes holes and mounds

Crown of Thorns:

  • Zero individuals observed
Publicado el sábado, 06 de agosto de 2022 a las 12:02 AM por langzi langzi | 0 comentarios | Deja un comentario