The document summarizes the categorization and analysis of zooplankton samples collected from inshore and offshore locations. Samples were collected using nets, sorted, and identified under a microscope. Several species were identified in each sample and counted. Statistical analysis found the inshore sample had slightly higher diversity but abundances were similar between locations. Median differences in species richness and relative abundances between inshore and offshore samples were found to not be statistically significant based on Wilcoxon and Mann-Whitney tests. This suggests the minor differences observed were likely due to chance rather than environmental factors.

1. The Categorization and Numerical Analysis
of Inshore and Offshore Zooplankton
Jessica Marie Watson
Department of Zoology, University of Aberdeen
1. Materials and Methods
An inshore sample of various forms of zooplanktonic life was retrieved using a mesh lined
net for a duration of fifteen minutes. The samples were then filtered, washed, and stored in
70% ethanol until analysis ensued. From this small sample a pipette, filled to its entirety, was
displaced into a sterile petri dish with approximately 4 millimeters of water to allow enough
space for specimen movement by the observer with a mounted needle. Individual species
were separated according to multifarious salient features including: antennule length, number
of swim feet, overall abdominal size and shape, positions of the eyes, mandible length, and
number of segments in the lower abdominal area. Each group was categorized according to
the aforementioned criteria using a British guide to Zooplankton provided by the lab
instructors. It was found advantageous to separate species into the four corners of the petri
dish using a clock method, at 12 o’clock, 3 o’clock, 6 o’clock, and 9 o’clock, at least for the
general characteristics.
From there further separation was demonstrated using smaller partitions of the
clock. Antennule length was the first feature to be analyzed and thus were sorted by
considerable length (T. longicornis) to diminutive or nonexistent (K. subtilis). Some species
that were identified did not fit into any of the aforementioned categories. These species were
held in the center of the clock until the others were defined. After that was complete, body
size seemed the most likely next step and thus, organisms were sorted by the size and shape
of the abdomen. From this, T. longicornis and C. finmarchicus were sorted into the “similar
body plans” 12 0’clock sector. From the manual of Zooplankton provided- this arrangement
concluded the aforementioned species were in fact, Calanoid Copepods.
Next, a specie was analyzed as having disjointed eyes, a long abdominal column, five
pointed abdominal segments, and small projections from the cephalic region. After further
analysis, it was concluded that this microorganism had been damaged either by the effects of
the environment or the mounted needle movement. Most of the projections were damaged,
but from the guide provided, other salient features were identified and demonstrated the
taxonomic categorization of C. vulgaris 1st larvae within the subclass Euphausiid. M.
squinado 1st zoea, was the next to be identified according to its long, pointed dorsal spine
and rostrum, particularly bulbous eye, small and thin maxilla, and sharp telson. The
aforementioned was placed isolated and documented as being in the subclass: Brachyuran
larvae. The last two species identified were completely dissimilar from each other as well as
from the previously annotated microorganisms. K. subtilis, with its arrowhead cephalic
region, lateral fins, and exceptionally long body was classified as a Chaetognatha while M.
merluccius was identified purely on its circular nature and organism located inside (The
organism was damaged and difficult to place).
Once the species were categorized each individual was ascribed an abundance rank
between one and five (“one” being one microorganism in the species category, “two” being
two to five, “three” being five to fifteen, “four” being fifteen to thirty-five, and “five” being
too copious to count). For this section, each species was already organized in the clock
method previously described. (For values of abundance rankings see “Results”). After this
data was recorded within a lab notebook, a relative rank was established between the Inshore

2. and Offshore samples. This was done by giving the sample with the highest specie number a
10 and then arriving at a fraction of that number for the less abundant sample. Due to the fact
that the Offshore sample was about one eighth as proliferative as the Inshore sample, a rank
of 1.3 was concluded (The numbers and graphs are located in the Results section).
Following this, the second sample containing Offshore life was analyzed using the
same methods previously annotated. From this sample only four species were identified (T.
longicornis, C. finmarchicus, E. reticulata, and S. armata). The latter two were organized by
their extreme differences and taxonomic backgrounds. E. reticulata had a cone shape with
ridges along the length and appeared damaged, S. armata had eight distinct abdominal
sectors, diminutive eyes, lengthy, ciliated antennules, and several swim legs. Each was
placed, again in a separate section of the clock and analyzed according to abundance rank.
After further analysis of the Inshore and Offshore was achieved, a Cyclopoida and
Calanoida were selected to be drawn within the laboratory notebook and studied. For this
selection, T. longicornis and O. similis were drawn and diagrammed according to the
Zooplankton lab manual provided. Differences in the two classifications of organisms was
also evaluated (available in Results).
2. Results
The individual results retrieved concluded that both inshore and offshore samples
contained relatively high amounts of C. finmarchicus and T. longicornis with negligible
amounts of other zooplanktonic life. Inshore samplings proved to be more speciated than
offshore with a nearly doubled amount of diversity. However, due to the fact that less water
was sampled in the offshore petri dish, the observation of less specie diversity was most
likely a result of human error. This is also the most likely explanation as to why the relative
rank of the offshore sample is nearly an eighth that of the inshore. The two species retrieved
with the most abundance may also have been due to sampling error, thus no conclusions can
be drawn about their abundance in their typical environment until repeated procedures are
secured and studied.
Regarding collected data, inshore and offshore samples had very similar maximum
species values collected, but very different inner quartile values. Offshore had a fourth of its
species abundances above 14, while inshore fell short. Offshore also had half of its
abundance above 10 and a fourth below 4. From this, one can conclude that Offshore had a
greater range of diversity and much more of its abundance fell within the inner quartiles.
Inshore had a slightly smaller range and more constricted abundance values. The Wilcoxon
test illustrates that the two medians are very close in quantity and provides data that if the
procedure were to be repeated, with 95% confidence, results will fall between 8 and 7.5 or 11
and 11.5 (in terms of median divergence). The Mann- Whitney test proves the
aforementioned to be accurate and sustainable with only about a 15% difference in median
values.
Collected relative rank data specifies that the maximum difference between samples is
roughly 8.7. One fourth of the data is greater than 3.3, one half of the data is greater than 1,
and the latter one fourth of the data is lower than -2 (without an absolute value
accommodation). The minimum value was roughly -9.7. The nearly 20 range spread
demonstrates very static environments. Both samples are diverse and subtracting one from
the other will allow results in equally as large negative integers as positive integers. The
Wilcoxon test chart shows an estimated median of about .75, with a likely range in the future

3. of -1.2 and 2.6. Such a low median proves that the difference in abundance between inshore
and offshore is actually very minimal when analyzed as an average. The Mann-Whitney chart
further demonstrates that the sample is not very far away from zero because the probability of
arriving at the aforementioned data is .385. The probability of this data being due to chance is
much greater than the .05 probability chi square value and thus, is failed to be rejected. Thus,
the species differences between inshore and offshore are very minimally divergent and are
due to chance. Because there is no significant difference further analysis of comparing the
median rank to the predetermined statistic of 10 is unnecessary because the direction of
amplitude in accordance to difference in quantity is effectively diminutive.
Table 1. This chart demonstrates an estimation of the relative abundance of inshore retrieval
on an individual basis. The chart exemplifies a numeric system derived by analysis of the
most abundant (with a score of 10) to a fraction of the most abundant. Scores demonstrated
above are as follows: “one” being one microorganism in the species category, “two” being
two to five, “three” being five to fifteen, “four” being fifteen to thirty-five, and “five” being
too copious to count. Table 1 presents a relatively high amount of C. finmarchicus and T.
longicornis while the other species viewed compare as negligible.
Table 2. This chart is an estimation of the relative abundance of offshore retrieval on an individual
basis. The chart exemplifies a numeric system derived by analysis of the most abundant (with a score
of 10) to a fraction of the most abundant. Scores demonstrated above are as follows: “one” being one
microorganism in the species category, “two” being two to five, “three” being five to fifteen, “four”
being fifteen to thirty-five, and “five” being too copious to count. This chart demonstrates a high
number of C. finmarchicus and T. longicornis and infinitesimal number of the remaining two species.

4. Table 3. This chart shows the sample with the highest specie number as a 10 and a fraction of that
number for the less abundant sample. Due to the fact that the Offshore sample was about one eighth
as proliferative as the Inshore sample, a rank of 1.3 was concluded.
Table 4. This box plot is a representation of abundance rank between inshore and offshore samples.
The greatest value, excluding any outliers regarding the inshore sampling is about 16 different species
collected. This number is only slightly higher than the offshore greatest value of 15 different species
collected. 25% of data regarding the inshore samples is greater than 11, while the Offshore had a
slightly higher value, where 25% of the data collected was above 14. 50% of the data arrived at for
inshore is greater than 9, while offshore is greater than 10. 25% of data is lower than 7 inshore and 5
offshore. Lastly, the lowest value achieved is 6 inshore and 4 offshore. Such a large spread requires
median analysis instead of mean interpretation. The inshore sample had a slightly lower median than
the offshore sample which allows the conclusion that offshore had a greater collection of samples with
10 or greater different specimens recorded.

5. Table 5. Wilcoxon Signed Rank CI: InSp, OffSp
Confidence
Estimated Achieved Interval
N N* Median Confidence Lower Upper
InSp 22 1 9.00 94.9 8.00 11.00
OffSp 23 7 10.00 95.0 7.50 11.50
Table 5. This chart illustrates that the two medians are very close in quantity. There are 22/ 23
recorded observations, the median is estimated as being 9/ 10 and we can be 95% confident that if
more experiments were evaluated the median difference would be between 8 and 7.5 or 11 and 11.5.
Table 6. Mann-Whitney Test and CI: InSp, OffSp
N Median
InSp 22 8.500
OffSp 23 10.000
Point estimate for η1 - η2 is -0.000
95.0 Percent CI for η1 - η2 is (-2.999,1.999)
W = 504.5
Test of η1 = η2 vs η1 ≠ η2 is significant at 0.9819
The test is significant at 0.9818 (adjusted for ties)
Table 6. This chart exemplifies a very minimal difference between the two medians, thus the medians
do not differ significantly. The median value of species richness for the inshore population is only
about 15% less than that of the Offshore sample (See figure 6). That difference was not significant
(Mann-Whitney W= 504.5, N=22&23, p < .385)

6. Table 7. This box plot shows an estimation of the relative abundance difference between
inshore and offshore species retrieval. The Y values represent a numeric system derived by analysis
of the most abundant (with a score of 10) to a fraction of the most abundant. Scores demonstrated
above are as follows: “one” being one microorganism in the species category, “two” being two to
five, “three” being five to fifteen, “four” being fifteen to thirty-five, and “five” being too copious to
count. The greatest value, excluding any outliers is an 8.7 difference between inshore and offshore.
25% of data is greater than 3.3, 50% of the data arrived at is greater than 1, 25% of data is lower than
-2, and the lowest value achieved is a -9.7 difference. Such a large spread requires median analysis
instead of mean interpretation. The RelAbDiff rankings are being compared to a constant value of
zero. Because the median is about 1, a significant amount of the data collected had a minimal
difference shown.
Table 8. Wilcoxon Signed Rank CI: RelAbDiff
Confidence
Estimated Achieved Interval
N Median Confidence Lower Upper
RelAbDiff 21 0.75 94.8 -1.20 2.60
Table 8. This chart shows that there were 21 observations with an estimated median of about .75. A
94.8% confidence interval is shown to prove that if one does this experiment many more times the
median of the differences would be somewhere between -1.2 and 2.6.
Table 9. Wilcoxon Signed Rank Test: RelAbDiff
Test of median = 0.000000 versus median ≠ 0.000000
N for Wilcoxon Estimated
N Test Statistic P Median
RelAbDiff 21 21 141.0 0.385 0.7500

7. Table 9. This chart demonstrates that our sample is not very far away from zero because the
probability of arriving at the aforementioned data is .385. If one were to test these results several
times over, they would arrive at similar results about 385 times per every 1000 trials. The probability
of this data being due to chance is much greater than the .05 probability chi square value and thus, is
failed to be rejected. Thus, the species differences between inshore and offshore are very minimally
divergent and are due to chance. The relative abundance difference between Inshore and Offshore
samples had a median value of .75 (with a 94.8% confidence range of -1.2- 2.6) The median was
close to zero (Wilcoxon sample test, W=141.0, N=21, p=.385). Because p > .05 there is no significant
difference between the relative abundance between the two samples.