You may think that “ocean acidification” has little direct connection to our local bays and harbors. The truth is that its impacts are greatest in shallow coastal waters.
Ocean Acidification (a lowering of the pH in our waters caused by increased CO2 in the atmosphere) causes, among other things, less calcium carbonate in the water that shellfish larvae and others require to grow their shells. After spending years improving our water quality and re-opening 2,500 acres to shellfishing for the first time in 45 years, this is obviously a concern in Hempstead Harbor.
Last night, the NYS Ocean Acidification Task Force held its second meeting – this time in Nassau County. Three very interesting presentations were made, which are summarized below.
Dr. Chris Gobler (Stony Brook University School of Marine and Atmospheric Sciences (SoMAS))
- Latest CO2 reading – 1/11/19 is at 409.44 ppm (400.0 was deemed to be the threshold).
- CO2 levels are increasing faster than originally predicted
- Calcifying organisms are vulnerable (shellfish, etc.)
- 2012 – most of NYSs fisheries are calcifying organisms
- Larval stages are most susceptible. When they are born, they have no shell and need to extract calcium from the water in order to grow them.
- Before the industrial revolution, CO2 levels were 250 ppm.
- Above 390 ppm affects shellfish.
- It does not just affect survival rates, but also growth rates.
- Fish are also sensitive to Ocean Acidification (OA). Larval fish do not survive as well.
- The same processes that lead to hypoxia (nutrient loading) will also lead to increased acidification.
- We see more severe OA in coastal waters than in the ocean.
- It is seasonal – Spring to Summer is highest.
- In summer of 2014, the western LIS was actually acidic (below pH 7.0). 8.0 is normal.
- Where you have low dissolved oxygen (DO), you have high OA.
- During nighttime, DO is lower and OA increases, particularly in shallow estuaries.
- About 5 years ago, almost nothing was known about the connection between low O2 and OA.
- In one experiment juvenile clams were able to grow with low oxygen. They also did alright with low pH. But when both are combined, their growth was slowed. In the real world, you have both together.
- Multi-trophic aquaculture – growing seaweeds and shellfish together can help.
- NYS does not regulate for pH – only DO.
- Growth of seaweeds can be detrimental to sea grasses but a help to shellfish.
- Where there is high CO2, sea grasses may benefit if there are no seaweeds growing.
- Macroalgae take CO2 out of the water. This is based on lab experiments. Then you’d need to harvest it. Kelp is one viable option.
- Carbonate goes down as pH goes up. You have to also measure alkalinity or DO when you measure pH.
Kyle Rabin (Long Island Nitrogen Action Plan, Long Island Regional Planning Council)
- The Long Island Nitrogen Action Plan (LINAP) is a multi-year initiative to reduce nitrogen in surface waters and groundwater. Partnership between DEC, LIRPC, and two counties.
- They have monthly conference calls for updates and coordination.
- Workgroups have been formed to address specific aspects (e.g. fertilizer).
- Part of their mission is to assess nitrogen levels, determine sources, and ID reduction targets.
- The NYS Ocean Acidification Task Force (OATF) and LINAP compliment each other.
- Suffolk’s initiatives:
- Subwatersheds wastewater plan
- Septic system improvement plan
- Septic / Cesspool Upgrade Program Enterprise – up to $20,000 is available to each homeowner
- Sanitary Code changes
- Sewering projects – including SC Coastal Resiliency Initiative – eliminating cesspools in sensitive areas. Public referenda are being held in 3 areas today.
- Harmful Algal Bloom Action Plan – created in 2017. Still being developed.
- Nassau’s initiatives:
- Subwatersheds planning – SoMAS is working on it using the same methodology as Suffolk.
- South Shore Water Reclamation Facility (Bay Park WWTP) upgrades
- South Shore Water Reclamation Effluent Diversion Project (19 Billion gallons a year of sewage will no longer be discharged to the Western Bays).
- Long Beach Wastewater Diversion to Bay Park
- Point Lookout Sewer Study
- Septic Improvement Program
- 60,000 septic systems on north shore
- Suffolk County Water Quality Improvement District Study – looking at establishing it. RPF has been released.
- LINAP Fertilizer Management Workgroup – recommendations are being finalized. Apply to homeowners and professional landscapers. Will be published in LINAP newsletter.
- South Shore Estuary Reserve (SSER) Western Bays Water Quality Monitoring – about to begin. Using a university.
- STEM Challenge – Grades 6-8. LI Water Quality Challenge – stormwater treatment or low impact landscaping
- Nutrient Bioextraction Initiative – seaweed and shellfish aquiculture to remove nitrogen in coastal waters. NYC DEP is looking to use ribbed mussels for this purpose as they are not susceptible to poaching from uncertified waters.
- Nitrogen Smart Communities – municipalities need to meet certain goals. Will be a pilot project
- Water Reuse Advisory Workgroup – workgroup was established. Roadmap produced. Golf Course irrigation being looked at.
- LI Water Quality Data Sharing System – one stop location for all data. Being developed. Over 60 entities collect data on LI.
- Outreach – monthly newsletter with 1,700 subscribers.
- https://lirpc.org/linap/2087/
- https://www.dec.ny.gov/lands/103654.html
- He would be glad to talk to the Protection Committees about their initiatives.
Dr. Frank Roethel (SoMAS)
- OA has long been known in lakes and streams.
- In some areas, they pump lime slurries into the waterbodies to reduce acidification.
- Lime has benefits for lakes – inexpensive, available, non-toxic, natural mineral, easy to distribute, dissolves in water.
- Very few studies on marine water.
- We have 14 WWTPs and Power Plants that all have discharges to marine waters. You could use them.
- New commercial construction in NYC – stormwater management designs. Stormwater is directed to large holding tanks and eventually discharged. These could also be used.
- East River and west side of Jamaica Bay are two of the worst areas. There are major facilities that discharge about 1+ billion gallons a day into these areas.
- Highly alkaline liquids – sodium hydroxide – readily available, easy to integrate into existing systems, highly corrosive
- Highly alkaline solids – lime – available as a waste product of scrubber residual from Waste to Energy facilities and coal fired plants – currently disposal costs on LI = $60 per ton.
- This could reduce the rate of acidification.
- To halt the increase in acidification – requires new technology and investment.
- To reduce acidification – not achievable in our lifetime.
- Estimate the amount of sodium hydroxide (NaOH) (ph 13) needed to affect pH – Assuming effluent is currently1 billion liters at pH 6 and if the goal is to raise the pH to 7, you would need to add 900 liters (=240 gallons). Is NsOH too corrosive for wastewater treatment plant workers to handle?
- If you use the same calculation and extrapolate to all NYC WWTP plants, you would need about 900 gallons per day.
- Other potential strategies:
- Portland cement manufacturing
- Portland cement is major contributor of CO2 emissions in the US and worldwide (7% of all C02)
- 90 million tons of Portland cement is produced in US / year
- In NY we use 3 million tons / year of Portland cement
- 1 ton of Portland cement produces 1 ton of CO2
- There are substitutes for Portland Cement
- Pulverized glass – has same pozzolanic properties as Portland cement
- Supports glass recycling
- Saves landfill space
- Replacement of a percentage of Portland cement can result in CO2 reduction
- Encourages sustainable construction
- We don’t know yet how durable it will be as compared with concrete over the long term.
- If there is an expanded bottle bill, perhaps some of those nickels can be directed to exploring this.
- Pulverized glass – has same pozzolanic properties as Portland cement
- Shell grinding
- cost effective
- no adverse impacts
- whole shells promote regrowth
- dissolution is a function of particle size
- optimal grain size would be a function of local conditions.
- Reduce use of chlorine as a sewage treatment plant disinfectant
- De-chlorination before discharge
- Sediment modification (put clean sand or crushed concrete or crushed glass on top of sediments)
- Enhancing marine vegetation
- Portland cement manufacturing
- Moving forward, we need more research and demonstration projects and legislation as well as partnerships with industry.