Central Basin of Lake Erie: Current Status

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1 Central Basin of Lake Erie: Current Status Dr. Bob Heath Professor Emeritus Kent State University and the Cleveland Water Alliance Waterkeeper Conference 23 October 2014 Watershed Stewardship Center Parma, OH

2 It s All Connected....

3 Lake Erie.... EB CB WB

4 Lake Erie.... EB CB WB SSB

5 Lake Erie is three lakes in one..... Western Central Eastern 8m 16m 64m

6 Lakes Through the Year in General Stratified lake Jan-Mar Apr May-June Jul-Aug Sept Oct - Dec

7 Lake Erie is three lakes in one..... Western Central Eastern

8 Dead Zones occur as.... as oxygen is consumed in the bottom waters faster than it s replenished oxygen is consumed faster in warmer water Lake Erie is warming: stratifying sooner bottom waters are warmer So... Hypoxic zones are more likely to recur

9 N Dynamics under AEROBIC conditions N 2 NH 4 + N-fixation (e.g. Anabaena) Internal Load (ZM) Nitrosofiers (e.g. Nitrosomonas) External Load O 2 Nitrifiers (e.g. Nitrobacter) NO 2 - NO 3 - O 2

10 N Dynamics under AEROBIC conditions N 2 NH 4 + N-fixation (e.g. Anabaena) Internal Load (ZM) Nitrosofiers (e.g. Nitrosomonas) External Load O 2 NO 2 - Nitrifiers (e.g. Nitrobacter) NO 3 - O 2

11 N-Dynamics under ANAEROBIC conditions Anammox (Planctomycetes) NH 4 + N 2 N 2 O Denitrification (e.g. Pseudomonas, etc.) NO 2 - NO 3 -

12 N-Dynamics under ANAEROBIC conditions Anammox (Planctomycetes) NH 4 + N 2 N 2 O Denitrification (e.g. Pseudomonas, etc.) NO 2 - NO 3 - NO 3 -

13 N N Leads to P-limitation Leads to N-limitation P P N:P > 15 N:P < 5 N Sediments CB Spring CB late summer

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15 Biogeochemistry Fe C P S N

16 It s All Connected....

17 CB watershed: mixed landuse

18 Courtesy: US/ACE

19 Hg PCB Courtesy: US/ACE

20 It s All Connected....

21 The issues in the Central Basin of Lake Erie.... Lake is getting shallower and warmer Lake is stratifying sooner and staying stratified longer Dead zones (hypoxia) occur regularly Decreasing habitat for cold-water fish Hazardous cyanobacterial blooms occur regularly - especially of Microcystis - cyanotoxins Invasion by non-indigenous species (e.g. Dreissena, Asian carp) Endocrine disruption of aquatic wildlife Heavy metal pollution especially mercury Beach closure advisories due to fecal coliform pollution Rivers as Areas of Concern (AOC)

22 The issues.... Lake is getting shallower and warmer Lake is stratifying sooner and staying stratified longer Dead zones (hypoxia) occur regularly Decreasing habitat for cold-water fish Hazardous cyanobacterial blooms occur regularly - especially of Microcystis - cyanotoxins, especially microcystin Invasion by non-indigenous species (e.g. Dreissena, Asian carp) Endocrine disruption of aquatic wildlife Heavy metal pollution especially mercury Beach closure advisories due to fecal coliform pollution Rivers as Areas of Concern (AOC)

23 Water columns in Lake Erie Epilimnion L/E is becoming shallower: Snow drought in L/Sup Diminished rain in L/H-M Cold-water Fish habitat but what if... USACE changes channel in St. Clair R.

24 Water columns in Lake Erie Epilimnion Cold-water Fish habitat Hypoxic zone

25 Biochemical Indicators of P-limitation... In samples taken from Central Basin of Lake Erie per μg Chl a Aug APA (μmol hr -1 ) P-debt (μmol P) P D I SRP (nm) P-turnover (min) Nutrient amend bioassay only P only N + P GREEN = P-limited

26 Microcystis blooms on Lake Erie....

27 Microcystis blooms on Lake Erie....

28 Microcystis blooms on Lake Erie.... Certain forms of N (e.g. urea fertilizers) favor Microcystis growth Can produce hepatotoxins (microcystins) - toxin is preferentially produced in N-limited waters (Orihel et al. 2012) - Total N is best predictor of toxin concentration (Scott 2013)

29 It s All Connected....

30 Do Microcystis blooms in WB affect the CB? Water flows from WB to CB Half-life of microcystin in lakewater ~ 10 days Why are some blooms more toxic than others?? What are microcystin effects on aquatic wildlife??

31 Do Microcystis blooms in WB affect the CB? Preventing recurrent HAB - Is this possible? - Is it economically feasible? Making sure our drinking water is drinkable - OEPA must set standards - drinking water plants must come into compliance

32 Other items of concern in Lake Erie.... Non-indigenous species: Dreissena (zebra and quagga) Bythotrephes (spiny water flea) Hemorrhagic septicemia virus (marine form) Asian carp (silver and bighead)

33 Other items of concern in Lake Erie.... Endocrine Disruptors DDT, PCBs, dioxins, pesticides, etc. Can be agonists or antagonists of natural hormones Disrupt normal functioning of endocrine system Alter sexual performance in many species: - diminish reproductive capacity in fish - gender alteration in Daphnia Alter gender-associated behaviors: - male gulls exhibiting female nesting behavior - HUMANS???

34 Other items of concern in Lake Erie.... Mercury pollution: - Largely airborne input from coal-fired power plants - Resides in sediments where certain bacteria can biomethylate it to methyl mercury compounds - Methyl mercury compounds are highly toxic - Diminished reproductive success in fish and aquatic birds - Fish advisories - Chronic effects in humans (neurological)

35 Other items of concern in the Central Basin.... Fecal coliform pollution of beaches: CSO following large storms E. coli can harbor toxic plasmids (e.g. O157:H7) Leading to hemorrhagic diarrhea and/or kidney failure Advisories posted at beach and online (OCM website)

36 Other items of concern in Lake Erie.... AOC Rivers with beneficial use impairments such as... degradation of fish and wildlife populations and habitat degradation of benthos drinking water restrictions degradation of aesthetics added costs to agriculture or industry 43 AOCs in the Great Lakes 4 AOCs in Ohio (Maumee, Black, Cuyahoga, Ashtabula)

37 Seventh largest economy in the WORLD Growth spot of the WORLD

38 It s All Connected.... P is biogeochemically connected to N, C, Fe, S The lake is part of the G/L Watershed The watershed is connected to the global Airshed Biology is connected to political, economic and social interests