Ecology of Small Marshes Using
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ECOLOGY OF SMALL MARSHES USING THREE DIFFERENT WATER SOURCES by Richard A. Grosz A Thesis Presented to The Faculty of Humboldt State University In Partial Fulfillment Of the Requirements for the Degree Master of Science May, 1992 ECOLOGY OF SMALL MARSHES USING THREE DIFFERENT WATER SOURCES by Richard A. Grosz Approved by the Master's Thesis Committee Stanley W. Harris. Chairman David W Kitchen William R. Sise Director, Natural Resources Graduate Program Date 92/W-253/06/15 Natural Resources Graduate Program Number Approved by the Dean of Graduate Studies Susan H. Bicknell ABSTRACT Waterbird use and aquatic vegetation were studied during seven seasons and in five units representing three water types at Arcata Marsh and Wildlife Sanctuary (AMWS), 1 July 1990-30 June 1991. Dominant vegetation types were cover-mapped and sampled for species composition, biomass, and stem density. The PH, salinity, turbidity, and water depth measurements also were taken at appropriate vegetation plots. The five study units represented, a saline basin (Klopp Lake) filled with water from Humboldt Bay, a freshwater unit (Butcher Slough Log Pond, BSLP) filled with well water; and three freshwater units filled with treated domestic wastewater effluent. The PH was greatest in the units in late spring except BSLP where it was highest in late fall. Salinity was greatest in Klopp Lake in mid fall. All four freshwater units had salinities of less than one ppt. The BSLP was significantly less (p<0.05) turbid than the wastewater units from late fall through summer. Dominant vegetation types included marsh pennywort (Hydrocotyle ranunculoides), lesser duckweed (Lemna minor), broad-leaved cattail (Typha latifolia), hard-stemmed bulrush (Scirpus acutus), and sago pondweed (Potamogeton pectinatus). Marsh pennywort and lesser duckweed also commonly occurred as understory species in the emergent cover types. Mean stem densities of broad-leaved cattail and hard-stemmed bulrush were greatest in summer and were greater in the wastewater units (p<0.05) than in BSLP. Biomass of sago pondweed was greatest in all freshwater units during mid fall. BSLP maintained submergent beds later into the fall than the wastewater units. The wastewater units developed iii iv heavy mats of lesser duckweed over most of their surfaces in the fall. Coverage of marsh pennywort mats peaked in early fall in Gearheart Marsh and BSLP and in summer in Allen and Hauser Marshes. Ninety-four species of birds were recorded. There was an annual total of 768,586 bird use-days on the five units. Almost 1/3 of the annual bird use-days occurred during late fall. Shorebirds (58.1 percent) and waterfowl, coots and rails (35.2 percent) accounted for 93.3 percent of annual bird use-days. Lowest bird use occurred in summer. Bird densities were greatest on Klopp Lake for diving ducks, large and small shorebirds, gulls, and terns. Based on relative area use, great blue herons (Ardea herodias) and ospreys (Pandion haliaetus) used Klopp Lake at greater than expected rates. BSLP and Allen, Gearheart, and Hauser units had similar patterns of annual bird use. Densities were greatest on these units for herons, egrets, puddle ducks, coots, rails and raptors. Annually, fish-eating divers, represented mostly by some resident pied-billed grebes (Podilymbus podiceps) used BSLP more than either Klopp Lake or the wastewater units. Black-crowned night-herons (Nycticorax nycticorax) used BSLP at more than twice expected rates but other herons used BSLP at less than expected rates. Cinnamon teal (Anas cyanoptera) and mallards (A. platyrhynchos) were most common on BSLP. The wastewater units were used at or more than 1.5 times than expected rates by herons, all puddle ducks, dowitchers (Limnodromus spp.), and Bonaparte's gulls (Larus philadelphia). The lesser scaup (Avthya affinis) was the only diving duck present on the wastewater units at expected or greater than V expected rates. American coots (Fulica americana) and rails used all four freshwater units at least 1.5 times more than expected. Continued annual marsh pennywort removal is strongly recommended, and guidelines should be established to stop encroachment of emergent vegetation into open water and submergent beds. If possible, a freshwater source should be routed into Klopp Lake to reduce high salinities and to allow for possible introduction of additional aquatic vegetation into the water column. An alternative to freshwater would be to introduce eelgrass (Zostera marina) into Klopp Lake. ACKNOWLEDGEMENTS Although credit is given to one person ultimately, a successfully completed masters thesis can only be accomplished with the support from family, friends, and professors. It is in this light that I would like to thank my mother and father, Donna and Terry Grosz, for always having faith in my abilities and for supporting me in my decisions. For showing me how to set goals, and more importantly how to achieve them. For teaching me how to look "down the road" and to be responsible for my actions. Lastly, in raising me with a hard work ethic realizing that nothing of value in life comes easy. I would like to thank Dr. Stan Harris ("Doc") for accepting me into the Humboldt Graduate Program. In giving me guidance throughout my graduate career and when need be, the extra time not only when dealing with my thesis but also in the classroom. Special thanks to Doc's wife Lorie for always offering their house to me and my wife Carrie, especially on holidays, but also on those "moments" notice occasions. Thank you Dr. Kitchen and Dr. Sise for your guidance in statistics as well as helping me with unforseen problems in my thesis. Carrie, how can I begin to thank you for the endless hours of typing, editing, putting up with the odd hours and late nights. In making sure that I had a warm meal after long hours of working on my thesis. For not letting me quit when times got tough and for providing me support and when time called for it, a push! Not only in being my wife, but also my best friend. Carrie thank you and I love you. vi TABLE OF CONTENTS Page ABSTRACT � iii ACKNOWLEDGEMENTS � vi LIST OF TABLES � x. LIST OF FIGURES � xi INTRODUCTION � 1 STUDY AREA � 4 METHODS � 8 Physical and Chemical Sampling � 8 Vegetation Sampling � 9 Wildlife Counts � 10 Statistical Methods � 12 RESULTS � 14 Physical and Chemical Parameters � 14 Vegetation � 18 Bird Use � 33 DISCUSSION � 64 Vegetative Considerations � 64 Waterbird Considerations � 69 MANAGEMENT IMPLICATIONS � 87 CONCLUSION � LITERATURE CITED � 93 APPENDIXES � 98 A� Mean Number and Standard Deviation of Birds Recorded per Survey on the Marsh Units of the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 1 July 1990 - 30 June 1991 (n=number of surveys) � 98 vii viii TABLE OF CONTENTS (Continued) � Page B Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Early Fall Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 1 July 1990 - 21 August � 1990 108 C� Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh Units During the Early Fall Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 1 July 1990 - 21 August � 1990 109 D Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Mid Fall Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 22 August 1990 - 12 October � 1990 110 E Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh Units During the Mid Fall Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 22 August 1990 - 12 October � 1990 111 F� Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Late Fall Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 13 October 1990 - 3 December 1990 112 G Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh Units During the Late Fall Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 13 October 1990 - 3 � December 1990 113 H Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Winter Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 4 December 1990 - 24 January � 1991 114 Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh Units During the Winter Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 4 December 1990 - 24 January � 1991 115 ix TABLE OF CONTENTS (Continued)� Page J Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Early Spring Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 25 January 1991 - 17 March 1991 �116 K Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh Units During the Early Spring Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 25 January 1991 - 17 March 1991 �117 L Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Late Spring Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 18 March 1991 - 8 May 1991 . �118 M� Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh Units During the Late Spring Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 18 March 1991 - 8 May 1991 119 N Dominant Vegetation Cover of the Allen, Gearheart, and Hauser Marsh Units During the Summer Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 9 May 1991 - 30 June 1991 . 120 O Dominant Vegetation Cover of the Klopp Lake and Butcher Slough Log Pond Marsh units During the Summer Season at the Arcata Marsh and Wildlife Sanctuary, Humboldt County, California, 9 May 1991 - 30 June 1991.