Lake Comparisons: Zooplankton and Benthos

Lake Comparisons:Zooplankton and Benthos With a few comments on Wolf Lake Helen Czech SUNY ESF

Zooplankton: Why are we interested? • Zooplankton are important indicators of aquatic systems • They can indicate predator-prey relationships • They effect phytoplankton and zoo populations are driven in turn by predatory inverts and fish • Rotifers are not well studied

Zooplankton Collection Methods • A Schindler trap was used to collect samples. • One sample per layer (epi, meta and hypo) was collected / lake (except for Green Lake, which had 2 / layer including a chemo layer). • Collected samples were washed into a collection bottle and then treated with Alka seltzer and eventually ethanol. • 2 whole lake net tows were taken from bottom to top • http://aslo.org/photopost/showphoto.php?photo=196

In Lab Analysis of Preserved Zooplankton • Zooplankton samples were counted in lab using a dissecting microscope and a tray. • 100 of the most common species (typically 3 -5) per layer

Wolf Lake www.fieldmuseum.org/.../images/wolflake_lg.jpg • Meta has greatest number of major groups • Rotifers are most abundant, followed by copepods • Common in samples were Calaniod and Cyclopoid copepods and nauplii • Observed rotifers: Keratella, Kellicotia and Polyarthra • One protozoan, Difflugia www.ksu.edu www.stetson.edu www.stetson.edu 192.171.163.165 www.serc.si.edu faculty-staff.ou.edu

Onondaga Lake • The epi had the greatest number of individuals • Cladocerans were the most common, followed by copepods • Bosmina was most common, followed by Daphnia and Cyclopoid copepods • The invasive Cercopagis was observed www.yale.edu www.dnr.cornell.edu www.nysm.nysed.gov

Arbutus Lake www.efloras.org • Copepods were the most common, and all zooplankton were more • common in the epi layer. • Chaoborus was the dipteran www.microscopy-uk.org.uk

Catlin Lake • Again, copepods and rotifers were the most common. • Numbers were not large, few in the samples www.gobacktothebasics.com

Oneida Lake • Data not available for analysis • Zooplankton observed are listed in Table 1 • The meta layer appears to have the greatest diversity www.esf.edu/.../gallery/oneida/xingye3small.jpg Table 1. Zooplankton in Oneida Lake www.microscope-microscope.org cfb.unh.edu

Green Lake • The hypo layer had the greatest number of cladocerans and copepods • Calanoids were the most common. • The chemo and mono layer had very few zooplankton

Lake Comparison • The Adirondack lakes have good diversity, but few zoo in samples. Copepods were common, as were rotifers • Onondaga Lake had a lot of zoo in comparison to the other lakes • Green Lake also had low numbers • Oneida had some diversity. • Typically the epi or meta had the greatest #

And let’s not forget benthos! Benthos are defined the organisms found inhabiting the bottoms of lakes, rivers and streams, and are often important indicators of health and diversity, pollution Common benthic organisms include molluscs, aquatic insects, oligochaetes

Benthos collection • Benthos were collected with an Eckman Dredge • Sample were seived and inverts were preserved in ethanol www.cee.vt.edu

Benthos we Found • Catlin Lake - Molannidae caddisfly, Chaoborus midge • Arbutus Lake: No data • Wolf Lake- Molannidae caddisfly, Chaoborus midge, Unionid mussel, Chironimidae • Onondaga Lake – YUCK – no benthos taken • Oneida Lake – Chironimidae, gastropoda, Zebra Mussel • Green Lake – we collected, but there was nothing in the sample.

Problems • Errors in data collection could be from improperly washing out the Schindler. • Human error in counting or improper mixing.

Wolf Lake • Very pristine lake • High diversity in zoo, but low numbers • Phyto numbers very low, which could explain low zoo numbers • Not a lot of silica, and not a lot of diatoms in the samples • pH is average, not too low • Seems to be oligotrophic, not a lot of N • Turbidity is low • DO was fairly high

Lake Comparisons: Zooplankton and Benthos