Natural History. Stewardship. Sustainablility.
INVERTEBRATES IN SOME VERNAL PONDS IN NE HARTLEY PARK.
SMALL CRUSTACEA, INSECT LARVAE & NYMPHS & OTHER ANIMALS
LIVE IN OUR SPRING PONDS IN THE FOREST.
MANY ELEMENTARY CLASSES EACH YEAR HAVE BEEN NETTING THEM UP
AND LOOKING AT THEM BEFORE RELEASING THEM BACK INTO THE WATER.
CHART 1
In every year the most common invertebrate found were mosquito larvae, even in the years that for some reason they were less abundant. The strong and consistent inverse changes in numbers of mosquito larvae and Daphnia may be due to the larvae feeding on young Daphnia.
Since the instructors’ focus were on environmental education and not on ecological data gathering, the data in chart 1 were from variable collecting and identification procedures according to what best fit the individual ages, abilities and instructional situations of each class. None the less, a few major trends appear. High numbers of Daphnia, an almost microscopic animal, that feed on microscopic algae, invertebrates and else, indicate productive ponds and non-polluted water. Their abundance varies widely, yearly and seasonally. However the numbers in the charts may be partly due to how many classes each year actually paid attention to them because of their small size.
CHART 2
Chart 2 shows the abundance from only the years of the highest collecting numbers in order to
reach for conclusions with more reliability. The accuracy of the
counting varied according to the age of the children and the instructor’s emphasis on
quantitative comparisons.
There were 2 aquatic critters not shown in this chart that had very high numbers which made the
relatively small numbers of other species hard to distinguish from each other in the chart.
Fairy Shrimp
are one of the animals that thrive in vernal ponds because of the lack of
fish predation. The fish are not in vernal ponds because the ponds dry up basically every year.
The numbers of these shrimp vary widely however from time to time for unknown reasons
everywhere in their entire range. The total numbers of the shrimp are not high in chart 2,
because they reflect numbers that are high sometimes and are low in other times, in each of
5 different ponds (Fairmont, Cutacross, Carolyn and Tamarack Ponds, with a few observations from Woodland Pond).
Fairmont Pond
Indicators of good water quality
are the joint presence or high numbers of caddisfly, damselfly,
dragonfly, mayfly, and stonefly. larvae or nymphs, predaceous diving beetles, clams, snails,
water-boatmen, -mites, -striders, and whirligig beetles, and low numbers of leeches and midges.
The aquatic fauna of these ponds indicated water quality little influenced by human activities.
Any further conclusions require identifying the critters to species, genus or family and identifying
and measuring the amounts of microscopic animals and algae.
Click here to see how salt pollution affects Woodland Pond, WATER QUALITY OF NE HARTLEY PARK STREAMS AND PONDS.
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