Managing Chesapeake Bay s Land Use, Fish Habitat, and Fisheries: Studies. Jim Uphoff & Margaret McGinty, Fisheries Service

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1 Managing Chesapeake Bay s Land Use, Fish Habitat, and Fisheries: Positive Image and or Negative Graphic Case Studies Jim Uphoff & Margaret McGinty, Fisheries Service

2 Maryland Fisheries Service has been looking at land-use and fish habitat dynamics in Chesapeake Bay Goals: Assessments and management strategies that reflect land-use impacts Guidance for planning agencies Public support for watershed conservation

3 Focus is on iconic managed species i.e., keep the common species common

4 Crash and recovery of Chesapeake Bay striped bass has become a fisheries management parable: Recovery follows reductions in fishing. Contaminant / larval survival hypothesis was neglected. In retrospect, it may link recovery and land use.

5 MD larval survival index (recruit per egg; 4 areas). Time period averages qualitatively follow abundance. If only overfishing, why aren t they random? Larval survival Historic Crash Rebuild Recovery

6 Improvement of habitat has also made striped bass more abundant in estuaries Restoration of DO in Delaware River Roanoke River flow management Savannah River restoration of flow and salinity regimes Chesapeake restoration and agricultural best management practices (?)

7 Why would agricultural conservation matter? 1. Spawning areas & nurseries aren t big (MD major ones plotted). 2. They receive nearly all watershed drainage. 3. Agriculture is the largest human land use (acreage). Bay Watershed Land-use Percent Developed 3.6% Agriculture 28.5% Forest 60.0% Other 7.8%

8 Choptank River postlarval survival improved with Caroline County BMPs that minimized erosion and runoff. Caroline County borders most of the nursery and had very good records. Acres in conservation 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 Conservation tillage Cover crops Postlarval S Postlarval survival 2,

9 MD Larval survival (4 areas) and attainment of phosphorus BMPs in Bay watershed %BMP estimates from Bay Program % Phosphorus BMPs Attained % P BMP Target Larval Survival Crash survival Rebuild survival Recovery survival Larval S

10 Positive role for agricultural practices in management of striped bass possible BMPs designed to reduce erosion, nutrients, and pesticides would reduce suspected contaminants (metals) 1970s Before BMPs. Decreased larval survival precedes overfishing Mid-1980s & 1990s Larval survival rises with BMPs, then levels off. Fishing cut drastically. Stock increases. Increased larval survival reinforced fishing restrictions - more recruits per egg.

11 During striped bass saga, Maryland s population & land-use changed million & 8% urban million & 16% urban Lawns now 23% of MD s Bay watershed Lawns = MD s largest crop million &?

12 Baltimore Washington DC Fisheries Service has examined subestuaries for effects of development since 2001 Spring spawning & larval habitat: egg-larval collections. Summer habitat: Juvenile-adult & DO

13 Presence-absence is main measure of fish response to development Ecologically meaningful Statistically robust Understandable Cost-effective

14 MD property tax structure density converted to percent impervious surface measures development. Tax maps updated annually. % impervious Towson U. satellite impervious estimates versus 2000 tax map structures per hectare Rural Suburb Tax map structures per hectare Observed Predicted City Lower 95% CI Upper 95% CI

15 Anadromous fish stream spawning surveys during explored development s effect. Three watersheds were sampled by volunteers. One was sampled by DNR. One had data from 1991

16 Percent of stream samples with herring eggs and larvae falls with impervious surface Percent with herring 100% 80% 60% 40% 20% 0% Mattawoman Trend Bush Piscataway Deer Percent impervious (development intensity)

17 Estuarine yellow perch larvae were sampled with plankton nets towed from boats 7 mm

18 Percent of plankton tows with yellow perch larvae, impervious surface, and dominant class of land cover (2010 estimates by MD Dept of Planning) Percent with larvae 120% 100% 80% 60% 40% 20% Brackish, agriculture Brackish, forest Brackish, urban Fresh, forest Fresh, urban 0% Percent impervious (development intensity)

19 Early larvae feeding success on zooplankton in 2010 & 2011 declined with development Mean fullness index Range = 0 to 1 Index = 0, no food Index = 1, completely full Percent impervious (development intensity)

20 Summer estuarine habitat: habitat occupation and dissolved oxygen

21 Mean summer bottom DO and percent impervious, by salinity classification (ppt), during Mean Bottom DO mg/l combined Salinity Class 5 to to 5 < Percent impervious (development intensity)

22 Case study ( & ) suggests freshtidal fish community threshold. Abundance of all species in summer trawl samples collapses. Geometric mean all species Mattawoman Creek Subestuary Percent impervious (development intensity)

23 Fish encounter multiple development-related stressors (Wheel of Misfortune) Watershed Road salt Sediment Flow change Streams Contaminants Nutrients Detritus Low DO Contaminants Altered food web? Endocrine disruptors? Harvest- Egg quantity Egg Quality Tidal-fresh estuary Salinity Zooplankton Contaminants Estuary Low DO Altered food web? Estuary Estuary Low DO Altered food web?

24 Severn River (brackish) yellow perch fishery & development, % Impervious Surface Egg hatch > 80% Lethal spawn salinity Hypoxia PCB s &? Fishery decline noted Egg hatch < 10% Fishery closed. Reopened without recovery

25 Impervious surface reference points for fisheries on resident species < 5% impervious - harvest restrictions & stocking; conserve watershed 5-10% - option to decrease harvest & stocking to compensate. Conserve & revitalize watershed 10-15% - Conserve & reconstruct degraded watershed >15% - options limited and localized

26 USGS. projections of development pressure in the Bay watershed and striped bass spawning areas (circled) Development Pressure Low Moderate High Very high

27 It s not just local or small scale: MD and VA supply most of the coast s striped bass National resource US value estimate - $6.9 billion in & 68,000 jobs MD value estimate $700 million & 8,200 jobs Harvest coordinated among states Development around spawning areas managed locally

28 Planning and zoning is fisheries management!!! Local development plans are a proactive approach to managing land use and fish habitat Work with other DNR units, state and federal agencies, local government, and stakeholders to protect fish habitat through resource friendly plans First applied to Charles County Comprehensive Plan and Mattawoman Creek Watershed in 2012

29 Want more information? Visit MD DNR, Fisheries Service s Fish Habitat and Ecosystems Program website: