bio 371 restoration of aquatic ecosystems - stony...
TRANSCRIPT
Bio 371 Restoration of Aquatic Ecosystems
Field and Laboratory course involving team-based student research
Overview
• 4 Lectures on near shore processes, the ecological role of oysters and oyster beds, the role of nutrient input into water quality
• Team based projects• Field trips (required) on Fridays or weekends in
September, October (first class trip September 8)• Three teams, each doing an assigned research project• At least two oral presentation/progress reports made by
groups• Course ends with oral reports, one day minisymposium• Grades based on overall participation, reports, one exam,
contribution to final paper, self-evaluation of participation (see syllabus).
Field Trips
• Located at Jamaica Bay, both on shore sites, and boat trip for one of the three teams.
• Whole-class Trips on Friday, Sept. 8, Friday, October 13, other dates for individual teams
• On trips, field sampling will provide basis for team lab work back at Stony Brook for two teams.
• Trips involve sampling from floating docks or in one trip (for one team) from a boat. If you don’t mind being on the water then this will be ok.
• If you cannot make these dates, cannot be flexible for other dates for trips, even on weekends, or feel discomfort about being waterside or on a boat, you may consider withdrawing from the course.
Resources
• Course web page:
http://life.bio.sunysb.edu/marinebio/bio371
Instructor: Jeffrey Levinton
TA: David Charifson
Other readings on the web site (up soon)
You can re-download syllabus from course web page
First field trip – Sept. 8
• Objective: general description of Jamaica Bay area
• Demonstration of some field techniques
Second class field trip – Oct. 13Tour of marsh restoration at JB – depart 7 AM
Later Field Trips
• These will continue sampling, and all teams may not attend all trips
• Team functions will be covered later on in lecture
What happens after the first field trip on September 8 (depart 8 AM)?
• Recitation meetings with David Charifson to discuss laboratory work, general progress (each team will make a brief progress report)
• Lab time for lab work and data analysis
What is the overall problem?
• Restoration: habitats and organisms have been removed from the system, and there are benefits to restore these habitats (marshes, oyster beds)
• Ecological Engineers: Some organisms have major effects on ecosystems, so their restoration has cascading effects on other species
• Ecosystem Services: The ecological engineering and other effects have measurable positive effects on aspects of ecosystems (biological diversity, biological production), which can be quantified as “services” performed both for the ecosystem, and for humans (e.g., food).
From Jackson et al 2001, Science
Why oysters?Specifically native eastern oyster
Crassostrea virginica• Restoration: Oysters were once extremely abundant in
New York waters, but are now nearly absent because of pollution and habitat destruction
• Ecological Engineers: Oysters create reefs, which support many other species and their filtration can remove plankton from the water, which benefits oxygen and removal of nutrients from water column (more on this later)
• Ecosystem Services: We can therefore quantify the benefits of the return of oysters in terms of ecological benefits and perhaps as a return of a food source! (Yum, love to eat those little pieces of marine snot!!)
What is the record for oyster eating in dozens per 10 minutes?
What is the record for oyster eating in dozens per 10 minutes?
•48 dozen!
What is the record for Rocky Mountain oyster eating in 10 minutes?
What is the record for Rocky Mountain oyster eating in 10 minutes?
• 3 lb, 11.75 oz.!
Reasons for restoring Crassostrea virginica
Historically oysters were very abundant in the region with large oyster reefs throughout NY Harbor and Haverstraw Bay.
Ecosystem restoration
water filtration
reef habitat for fishes and invertebrates
nutrient cycling
possible resistance assistance for storm surge
Not fishery motivated, yet
Intertidal oyster bed – eastern oysterCrassostrea virginica
Oyster Restoration Projects - New York Harbor and Haverstraw Bay/Tappan Zee
Objectives:
1. Map of growth, survival, physiological condition, reproduction, disease
2. Use habitat quality maps, hydrographic maps, hydrographic modeling to design a system of sustainable oyster reefs
.Jamaica
BayRaritan
Bay.
Pier 40Hudson River
.
Haverstraw Bay
..... .
ShelterIsland
Study Locations
Hudson RiverPier 40, Manhattan
Jamaica Bay
Haverstraw BayTappan Zee Bridge
Concerns about Water Quality
Shelter IslandMashomack Preserve
(Control Site)
“Water quality control site”
.Jamaica
BayRaritan
Bay.
Pier 40Hudson River
.
Haverstraw Bay
..... .
ShelterIsland
.Jamaica
BayRaritan
Bay.
Pier 40Hudson River
.
Haverstraw Bay
..... .
ShelterIsland
INFLUENCED BY LOW SALINITY
COASTAL SALINITY BUT HIGH DISEASE RATE
Salinity through time at all 9 study sitesMid June to early November - 2008
What is salinity?
Why measure salinity?
How do we measure salinity?
Oxygen through time at cage depths
What is dissolved oxygen
Why do we measure it?
How do we measure it?
Why measure temperature?
Why measure chlorop
Methods – General Overview
1. Deployed oysters (from Fishers Island) in cages off of docks at each site.
2. Study period = June 2008 to December 2009.
3. Regularly monitored survivorship, growth, condition index, gonad ripeness, and disease prevalence.
4. Monitored environmental parameters including temperature, salinity, dissolved oxygen, and size fractionated chlorophyll*.
5. Conducted a preliminary oyster settlement survey at Haverstraw Bay sites.
Why measure chlorophyll??
Methods – Cages
Suspended from docks 2 meters below surface
Methods – Oyster monitoring
Survivorship and growth monitored in the field once every 2 weeks
counted live and dead
measured shell height – WHAT IS SHELL HEIGHT?
Methods – Oyster monitoring
Disease testing conducted once per year at all sites in early September
histopathology
assessed prevalence and intensity of the oyster parasite Perkinsus marinus (i.e. Dermo infection) using Ray’s Fluid Thioglycollate Medium (FTM) technique (Ray 1966, Fisher and Oliver 1996); also MSX Haplosporidium nelsoni
WE WILL NOT DO THIS
Methods – Environmental monitoring
Water temperature monitored
Salinity and dissolved oxygen measured with YSI 85 handheld instrument [DEMONSTRATION AFTER LECTURE]
Size-fractionated chlorophyll measured to get distribution of cell sizes
Methods – Oyster settlement
Assessed prevalence of oyster settlement at Haverstraw Bay sites
Attached small mesh bags (~40cm x 15cm) filled with clean oyster shell to sides of cages
Survivorship was high (>88%) at 7 of 9 study sites.Substantial mortality occurred at northernmost (HB-5) and southernmost (Pier 40) Hudson River sites.
. HB-5
. Pier 40
Shell growth rates differed among sites. Growth was highest at Shelter Island and Jamaica Bay, and lowest within Haverstraw Bay;
GROWTH STRONGLY CORRELATED WITH SALINITY.
Crassostrea virginica growth is proportional to salinity
LEADS TO FOCUS ON JAMAICA BAY
MOST OF BAY IS WITHIN GATEWAY NATIONAL PARK
MAJOR AREA FOR BIRD MIGRATION
BUT: HABITAT IN DANGER, MARSHES DECLINING, TERRAPINSIN DECLINE, WATER QUALITY AFFECTED BY 4 WASTE WATER TREATMENT PLANTS
?
No oysters!?
WHAT IS THE PROBLEM WITH JAMAICA BAY
THERE WERE LOTS OF OYSTERS UNTIL 1920’S – POLLUTION, ANOXIA (LACK OF OXYGEN) – OYSTERS DISAPPEARED
IN RECENT DECADES:
POLLUTION ABATED SOMEWHAT, N input reduced by ~halfSTILL ENORMOUS AMOUNTS OF TREATED SEWAGE ENTERS BAY (4 MAJOR SEWAGE TREATMENT PLANTS)NO OYSTER LARVAE SETTLE IN BAY (WE HAVE TO LEARN ABOUT LARVAL CYCLE)DISEASE COULD BE A PROBLEM (WE NEED AN INTRODUCTION TO DISEASE)
CAN WE RESTORE OYSTERS TO JAMAICA BAY OR ANYWHERE ELSE?
Factors in Successful Restoration:
1. Growth rate, survival, physiological condition,
reproduction, disease (study of oyster performance at
various sites)
2. Sustainability – oysters have planktonic larva, requires
larval source OR establishment of new metapopulation
network of reefs, retention of larvae within system
(modeling of water circulation)
3. Habitat - Suitable bottom, use of artificial reef substrata,
use of cage culture (choices based on habitat, goals)
4. Compatibility of restoration with ecosystem function,
properties of native populations (ecosystem analysis,
population genetic studies)
Sustainability of Reefs Requires
a. regional recruitment
b. construction of sustainable metapopulation
c. modeling of metapopulation structure (water quality, habitat quality, flow, rainfall, larval behavior)
loss
input
Source
Sink
Sustainability of Reefs Requires
a. regional recruitment
b. construction of sustainable metapopulation
c. modeling of metapopulation structure (water quality, habitat quality, flow, rainfall, larval behavior)
loss
input
Source
Sink
No regional source
• coupled hydrodynamic-water quality model• hourly water speed & direction plus,
salinity, temperature and dissolved oxygen for every cell
Based on Jamaica Eutrophication Model
Jamaica Bay Project - HRF, HydroQual, Stony Brook
LEADS TO QUESTIONS
++ARE THERE WATER QUALITY VARIATIONS THAT MATTER?
++HOW DO OYSTERS RESPOND TO THIS VARIATION
++WHAT GOOD ARE OYSTERS IF WE RESTORE THEM?
++ARE THERE OTHER SPECIES THAT COULD BE USED TO SERVE THE SAME ECOSYSTEM FUNCTION?
OUR FIELD TRIP NEXT WEEK
What are the 3 team functions?• Team 1: Oyster performance: study of the role of
locality-water quality and overall potential effect of oysters on water column (feeding and oxygen consumption)
• Team 2: Water quality: a study of water quality in different locations in Jamaica Bay based on a boat transect and regular sampling at two localities at either end of a water quality gradient
• Team 3: Experimental nutrient studies. Experimental manipulation of water collected from two localities to see effects of different nutrients and their possible limitation to phytoplankton growth.
Introductory Lecture
• Sea water?
• What are tides?
• What is an estuary?
Water molecule
• Asymmetry of charge distribution on water molecule - increases ability to form bonds with ions - makes water excellent solvent
Water properties
• High heat capacity (0.9)
• High heat of evaporation (590 cal/g)
• High dissolving power
• High transparency (absorbs infrared, ultraviolet)
Latitudinal Gradient of Sea Water Temperature
Vertical Temperature Gradient: Open Tropical Ocean
Vertical Temperature Gradient: Shallow Temperate Ocean
Heat Changes in the Ocean
Additions Losses
Latitudinal gradient
of solar heating
Back radiation of
surface
Geothermal heating Convection of heat
to atmosphere
Internal Friction Evaporation
Water Vapor
Condensation
Seasonal changes in temperature
• What is the general pattern? (draw a diagram on blackboard)
• Why does this matter for oysters? (place important milestones of oyster function at different times of year)
Salinity
• Definition: g of dissolved salts per 1000g of seawater; units are o/oo or ppt or psu (practical salinity unit – from conductivity, discussed in a minute)
• Controlled by:
+ evaporation, sea-ice formation
- precipitation, river runoff
Salinity in open ocean is 32-38 o/oo
Salinity
• Salt in sea water depresses freezing point to about -2C
Important elements in seawater
• Chlorine (19,000 mg/l)
• Sodium (10,500
• Magnesium (1,300)
• Sulfur (900)
• Calcium (400)
• Potassium (380)
• Bromine (65)
• Carbon (28 - variable)
Latitudinal salinity gradient
Excess of evaporation over ppt in mid-latitudesExcess of ppt over evaporation at equator
Measurement of Salinity• Measured by chemical titration, conductivity,
index of refraction
• Chlorinity: g of chlorine per 1000 ml of seawater
• Salinity = 1.81 x chlorinity
Measurement of Salinity• Conductivity is the way we measure salinity.
Relative to a standard we get practical salinity units or PSU
• Salinity in open ocean in this region is about 30-32 psu, but it goes all the way to freshwater (0 psu) in estuaries.
• In Jamaica Bay salinity varies from ca. Low 20s to 30 psu
Seawater density (mass/volume)
• Influenced by salt, no maximum density at 4 °C (unlike freshwater)
• Density measure of seawater at temperature t
st= (density - 1) x 1000
st increases with increasing salinity
st increases with decreasing temperature
Special significance: vertical density gradients
Why Density Matters: Vertical density gradients
• Stratification occurs in quiet water when you get warming from above which creates surface low density, high temperature water over cooler water at depth
• Stratification occurs in quiet water when fresh water comes from rivers and low salinity water comes to ride above high salinity water
• Consider Jamaica Bay: <10m depth, strong tide, wind. Is it stratified?
Oxygen
• Needed by most marine organisms
• Added to seawater by photosynthesis, but subtracted by respiration
• Solubility of oxygen increases with decreasing temperature, and increases with decreasing salinity
• Measured as mg L-1 or ug ml-1
Oxygen
• When you have lots of nutrients, you get lots of phytoplankton
• Not all phytoplankton is eaten and is decomposed by bacteria
• Oxygen in water column declines (hypoxia) or is absent (anoxia)
• Animals die
Development of hypoxia in an estuary. (a) Normal situation: much of thephytoplankton is grazed and bottom waters are oxygenated; (b) nutrient input from sewage stimulates phytoplankton growth, and some dead phytoplankton sink to bottom waters; bacterial decomposition reduces oxygen, and other material sinks to bottom sediment, where more oxygen is consumed from bottom waters; (c) oxygen is removed from bottom waters and benthos die
Dead zone on shelf off the mouth of the Mississippi River in 1993, 1998
Waves
• Dimensions
Wave Length L
Amplitude H
Velocity V=L/t
Whole water column is NOT moving horizontally!
Waves
• When depth < L/2: waves “feel bottom”
• When H/L > 1/7: wave is unstable and collapses (breaks)
Beaches
• Many beaches exposed to direct wave and erosive action
• Some sandy beaches are more protected, very broad with low slope and dissipate wave energy near the low tide mark
Low tide
Protected beachExposed beach
Beaches 2
• Profile more gentle in summer; fall and winter storms cause erosion and a steeper profile
Beaches 3• Longshore currents, riptides are common
features, causing erosion and transport of sand
Tides
Sun
Sun
E
E
SpringTide
NeapTide
E = Earth
mm
m
m
m = Moon: grav. effect is 6x sun
water
• Spring Tides - greatest vertical tidal range, highest high, lowest low – sun and moon and earth close to in line
• Neap tides - smallest vertical tidal range – sun earth-moon at ca. right angle
Tides
• Tides differ in different areas; function of basin shape, basin size, latitude
• Amplitude varies, evenness of semidiurnal tide varies
Tides
Connecticut - even tides Washington State - uneven
Spring Neap
Bay of Fundy
Estuaries
• Body of water where freshwater source from land mixes with seawater
• Often results in strong salinity gradient from river to ocean
• Salinity may be higher at bottom and lower at top, owing to source of river water that comes to lay on top of sea water below, or mixes with the sea water to some degree
Estuaries 2
Chesapeake Baywith summer surfacesalinity. Dark blueareas: tributaries have salinity< 10 o/oo
Cape Fear Estuary and Coast, N.C.
Estuaries - types
10
10
20
2030
Sea water
Fresh water layer
Highly stratified estuary
Moderately stratified estuary (wind, tide mixing)
Vertically homogeneous estuary
Hudson, Chesapeake Bay
Hudson River salinity strongly affected by precipitation
Salinity model shows importance of changes of regional precipitation on oyster survival
Quiz one
• What is the formal species name of the eastern oyster?
• What is one reason that it would be useful to restore oyster reefs where they have disappeared
• What is the simple best way (=unit) to put a value on ecosystem services of an oyster reef?
• What is the main reason that water is such a good solvent?
Now…we begin to form teams!
• Water quality – measuring water quality in boat transects, analyzing data on line to determine history of water quality
• Nutrient limitation – adding different nutrients to determine which are more limiting to phytoplankton growth
• Oyster performance – study of oyster performance (feeding and oxygen consumption) of oysters kept in waters of differing quality
The End