Lecture 18, 03 Nov 2003 Chapter 9 (Aquatic Ecosystems) Student Presentations Conservation Biology ECOL 406R/506R University of Arizona Fall 2003 Kevin Bonine

1.Aquatic Ecosystems (CH9) 2. Thank you cards 3. Syllabus Shuffle (Bob Steidl back one class) Overview of Reserve Design Listed Species Reserve Readings for Wed (SDCP):

Chapter 9 group presentations Monday: 8 minute highlights presentation, + 2 min QnA (board, or overhead, or powerpoint [ late Sunday ]) Amy Tendick, Galia Bobman, Aurora Fabry-Wood, Leonides Corral Ben Joslin, Andrea Vasquez, Bridget Barker, Louise Misztal Christopher Deegan, Michael Gilliland, JD Friedrichs Dana Backer, Cori Carveth, Sarah Hartwell, Jenna Ramsey Erica Sontz, Meghan Jarvie, Ginny Newsome, Linh Nguyen Maeveen Behan, Justin Dodds, Lauren Merin Pages:

Tendick Bobman Fabry-Wood Corral

Joslin Vasquez Barker Misztal

Conservation Challenges in Freshwater Habitats Eutrophication Acidification Habitat Alteration –Invasive plant species –Invasive invertebrates –Invasive vertebrates

Conservation Challenges of Freshwater Habitat

The Issues Eutrophication Acidification Habitat Alteration by NIS’s –Plant –Animal

Eutrophication Natural process of the aging of a lake In a young lake, the water is cold and clear, and supports little life Streams drain into the lake, introducing nutrients such as nitrogen and phosphorus, which encourage the growth of aquatic organisms The lake's fertility increases, and organic remains begin to be deposited on the lake bottom

Eutrophication Silt and organic debris increase on lake bottom, lake becomes shallower and warmer, less oxygen Warm-water organisms supplant those that thrive in a cold environment Marsh plants take root in the shallows and begin to fill in the original lake basin and the lake gives way to a bog, and finally into land Depending on climate, size of the lake, and other factors, the natural aging of a lake may span thousands of years

Eutrophication Pollutants from man's activities can radically accelerate the natural aging process Lakes have been severely eutrophied by sewage, agricultural and industrial wastes

Eutrophication Primarily from increased nitrates and phosphates, which act as plant nutrients Stimulate the growth of algae Cause unsightly scum and unpleasant odors Reduction of dissolved oxygen, which is vital to other aquatic life Other pollutants flowing into a lake may poison whole populations of fish Decomposing remains further deplete the water's dissolved oxygen content

Pollutants In 1996, the EPA reported to Congress in the National Water Quality Inventory –Approximately 40% of the nation's surveyed lakes, rivers, and estuaries were too polluted for such basic uses as drinking supply, fishing, and swimming –The pollutants include grit, asbestos, phosphates and nitrates, mercury, lead, caustic soda and other sodium compounds, sulfur and sulfuric acid, oils, and petrochemicals

Pollutants Manufacturing plants pour off undiluted corrosives, poisons, and noxious byproducts The construction industry discharges slurries of gypsum, cement, abrasives, metals, and poisonous solvents A pervasive group of contaminants is polychlorinated biphenyl (PCB): components of lubricants, plastic wrappers, and adhesives Hot water discharged by factories and power plants causes thermal pollution, lower oxygen

Acidification Hydrogen sulfide, NO x and SO 2 from coal burning for electricity Nitrous oxide from car exhaust Combine with water to form sulfuric and nitric acid

Acidification Rain is slightly acidic Buffering by carbonates, some freshwater systems are more susceptible to acidification High acidity affects reproduction of fish, amphibians and invertebrates Direct mortality Change in chemical reactions, metallic ions may precipitate out of solution Acidification can happen rapidly: pH from 7 to 4 in 24 hour period in Scotland during heavy rain, massive fish kill

Habitat Alteration By Nonindigenous Species Aquatic Enviroments Vulnerability 1.Recent disturbance 2.Predators absent 3.Effective Competitors absent Invasion by Aquatic Plants 1. Introduction Usually by humans 2. Dispersal occurs after survival and reproduction 3. Adaptation via selection and establishment 4. Colonization

Eurasian Water Milfoil Reproduces vegetatively Often transported by Human activity Reproduces Rapidly

Distribution in the United States

Other Aquatic Invaders 1. Purple Loosestrife –Chokes out natural vegetation in shallow water 2. Water hyacinth –forms dense mats in deep water

Animal NIS’s in Freshwater Properties: –High reproductive rates –Wide environmental tolerances –Large dispersal distances 3 Examples:

The Zebra Mussel

The Spread of…

The Carp (Cyrinus carpio)

The Nile Perch (Lates niloticus)

The demise of the Haplochromis spp. of cichlid fish

Take Home Lesson? –“ Managers must consider that if (there are chemical alterations to a system or a) nonindigenous (species) enters a system, habitat management and conservation strategies may have to be fundamentally altered to preserve biodiversity.” Van Dyke 2003 (pg 238)

Deegan Gilliland Friedrichs

Conserving Aquatic Habitats Managing Sedimentation & Eutrophication

Why?

Mmm...

… yummy!

The Culprits Us! (surprise)

Primary Cause: Erosion modern agricultural runoff urban sewage & waste disposal land development -- “impermeability”

Sociopolitical causes need sociopolitical remedies: We must enact laws & policies to: Reduce chemical fertilizer use Remove compounds from urban discharge Reduce agricultural & landscaping erosion

Urban Abatement no.1

Urban Abatement no.2

Restoration Dredging Chemistry Biomanipulation

Dredging Remove & Purify Contaminated Sediments

Chemistry -- Riplox method Oxidize sediment surface to precipitate out phosphorus. Additional reactions raise O 2 levels, stabilize pH, & encourage denitrifying bacteria in the sediment to release excess nitrate as gas into the atmosphere.

Bioremediation

Bioremediation continued

Alternative Stable States Nutrient inputs Fish populations Macrophyte & Periphytic algal populations Turbidity is balanced by:

Thanks.

Backer Carveth Hartwell Ramsey

Legislation and Management for Freshwater Environments Sarah, Jenna, Cori and Dana Monday November 3, 2003

The Wild and Scenic Rivers Act Most significant legislation protecting streams and rivers Introduced in 1968 Verde River, Arizona

What is it?? Under this act, a stream or section of a stream is designated as wild and scenic Protected from any action by any federal agency that would adversely affect its water quality

Problems… Less than 2% of U.S. streams were deemed sufficient to merit protection under this act This means that less than 100,000km out of 5.2 million km’s are protected San Pedro River, Arizona

Water Pollution Control Act, 1972 Amendment to the Clean Water Act Directed EPA to “restore and maintain the physical, chemical and biological integrity of the nation’s waters” and to enhance all forms of aquatic life A more biologically oriented approach to protecting the nations waters

Problems… Only chemical standards enforced –Does not ensure that entire ecosystem is functional –Many impacts that degrade aquatic systems are not detected by chemical monitoring Cienega Creek, Arizona

Indices of Biotic Integrity (IBI) Ecologically based measurements of water quality A particular taxon (i.e. fish) is rated and scored based on 3 different attribute groups –Species Richness and Composition i.e.Number and identity of benthic species –Trophic Composition i.e. Percentage of omnivores –Fish abundance and Condition i.e. Number of individuals with disease, fin damage and skeletal anomalies

IBI’s Continued.. Site scored and assigned an “integrity class ranking” Few fish present, most introduced species Very Poor12-22 Growth rates and condition factors depressed Poor28-34 Signs of deteriorationskewed trophic structure Fair40-44 Species richness below expected Good48-52 Comparable to best situation w/out human disturbance Excellent58-60 AttributesIntegrity Class of SiteTotal IBI Score

Advantages… Focuses on distinct attributes of the system Inexpensive Simple and sensitive to ecological change Incorporates professional ecological opinion

International and National Legislation for Wetlands Wetlands were one of the first cases in which international legislation focused on the protection of an ecosystem instead of a species. The Ramsar Convention, was the first global conservation convention to focus on the wetlands ecosystem. The convention obligates its signers to identify and designate at least one wetland in their country as a “wetland of international importance” and to establish wetland nature reserves.

Canada’s federal policy on wetland conservation is one of the best national examples of implementing the ideals of Ramsar and has experienced remarkable success.

The Canadian policy articulates strategies for sustainable use and management of the nation’s wetlands. Provides for the maintenance of overall wetland function. Enhances and rehabilitates degraded wetlands. Recognizes wetland functions in planning, management, and economic decision making in all federal programs Secures and protects wetlands of national importance. Uses wetlands in a sustainable manner. Allows no net loss of wetlands on federal lands and waters.

The U.S. has designed a number of legislation acts to address wetland conservation in an act to increase preservation and restoration of these areas.

The 1985 Food Security Act, aka “Swampbuster” is designed to stop the process of draining wetlands in private agricultural lands. Denies most U.S. Department of Agriculture benefits to farmers who drain wetlands on their land. Creates an eligibility requirement for farmers to receive Administration loans and other benefits.

Wetland Reserve Program (WRP) Provides for payment of subsidies to farmers who remove croplands from production in former wetland areas and to reestablish the land as wetlands To enroll in WRP, the landowner’s plan must include drainage alterations and the establishment of marsh plants on the enrolled site.

Other examples of U.S. programs or acts implemented to protect and preserve wetlands. Clean Water Act Migratory Bird Hunting and Conservation Stamps Federal Aid to Wildlife Restoration Act Wetlands Loan Act Land and Water Conservation Fund Water Bond Program Executive Order Floodplain Management Executive Order Protection of Wetlands Coastal Zone Management Act Payment-in-kind program

Despite conservation efforts, wetlands loss in the U.S. still continues in part because: There is a lack of agency coordination in wetland conservation. Most legislation does not regulate private activity on private lands (cause of majority of wetland loss). Some U.S. legislation still encourages the draining of wetlands. For example the U.S. tax code encourages farmers to drain and clear wetlands by providing tax deductions for many types of development activities.

Setting Priorities for Conservation in Freshwater Habitats WWF-US criteria for assessment of lakes and streams 1. Biological distinctiveness 2. Conservation status

Gives priority to regions that contain systems that contribute to biodiversity 1. Globally outstanding 2. Continentally outstanding 3. Bioregionally outstanding 4. Nationally important Priority declines as the importance of the system decreases

Rankings... I Critical (intact habitat reduced to small, isolated patches; small probability of persistence over the next 10 years without immediate action) II Endangered (intact habitat of isolated patches with low to medium probability of persistence over the next 10 years without immediate or continuing protection)

III Vulnerable (intact habitat remaining in large and small areas, persistence is likely over the next 10 years with protection and restoration) IV Relatively Stable (disturbance and alteration in certain areas, but overall stable; external practices unlikely to impact habitat) V Relatively Intact (minimally disturbed)

Rule-Based Models Used to determine if habitat loss or environmental change are random Evaluate possible mechanisms of distributional changes in a species

Disappearance of Frogs Isolation model: due to distances between changes in distribution ponds Succession model: changes in distribution due to altered vegetation in and around ponds Null model: changes in distribution were random

Results of the study showed that the Succession Model was correct Frogs could best be preserved by managing the vegetation Rule-based models require minimal data, don’t necessarily need to prove that changes in vegetation cause frog declines, only that managing vegetation may help frogs more than another type of plan

Sontz Jarvie Newsome Nguyen

Marine Habitats and Biodiversity

Marine Habitats Intertidal Pelagic Benthic Abyssal Coral Reefs Estuaries Seagrass Beds (benthic)

Coral Reefs Shallow, tropical water 20 o N and S of equator Indo-Pacific, Western Atlantic, Red Sea rg/Coral%20Forest/ma p.html

Coral Reefs Structure-coral polyps secrete calcium Nutrients-erosion of reefs releases calcium Water quality-sponges filter water Light-coral forms in well- lit waters, favorable for photosynthesis

Benthos Ocean bottom, excluding the deepest areas Sand, silt and decomposing organic matter Often dark Often cold Nutrient rich

Seagrass Beds 15% decline in past decade Flowering plants Food resource, nursery, habitat Prevent erosion Reduce wave impact Filter water

Hydrothermal Vents Mid-ocean ridges, tectonic plates Chemosynthetic bacteria Huge taxonomic diversity Old? Relict species? Metapopulations?

Whale Fall Communities Succession of communities Decomposition of bones yields hydrogen sulfide DNA analyses of fauna Implications for whaling?

Major threats to Marine Habitats: 1. Exploitation of commercial species 2. Direct destruction of marine habitats 3. Indirect degradation of marine habitats

1. Exploitation of Commercial Species Maximum Sustainable Yield (MSY): –Used to manage fisheries as renewable resources –Calculated based on catch per unit effort –Reproductive surplus was the only requirement for a sustainable fishery –Not used in fisheries anymore because it caused depletion in fish stocks

1. Exploitation of Commercial Species Current Estimates: –70% of the world’s fish stocks are exploited or depleted –45% of all species are over-harvested

1. Exploitation of Commercial Species Over-harvested Populations: –Show widely ranging cycles of high and low abundance. –Do not necessarily show a strong correlation between recruitment and number of adults present. –Do not necessarily show advanced warning of population decline.

Effects 1. Exploitation of Commercial Species: Effects Removal of a prey species may reduce the populations of predators. Ex. Decline of sea otters in CA following over-fishing of abalones. 2. Removal of predator species disrupts equilibria of prey species.

Effects cont. 1. Exploitation of Commercial Species: Effects cont. 3. The take of non targeted species contributes to exploitation problems. Ex. In shrimp fisheries, the discarded by- catch can exceed that of the targeted catch.

2. Direct destruction of Marine Habitats Examples of Direct Destruction: –The use of explosives to harvest coral reef species. One blast can devastate 1000m 3. –Trawling nets destroy complex and diverse communities on the ocean floor. (figure 9.15)

Behan Dodds Merin

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