DOCSLIB.ORG

The Rise of Ruppia in Seagrass Beds: Changes in Coastal Environment and Research Needs

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Rise of Ruppia in Seagrass Beds: Changes in Coastal Environment and Research Needs In: Handbook on Environmental Quality ISBN: 978-1-60741-420-9 Editors: E. K. Drury, T. S. Pridgen, pp. - © 2009 Nova Science Publishers, Inc. Chapter 12 THE RISE OF RUPPIA IN SEAGRASS BEDS: CHANGES IN COASTAL ENVIRONMENT AND RESEARCH NEEDS Hyun Jung Cho*1, Patrick Biber*2 and Cristina Nica1 1 Department of Biology; Jackson State University; 1400 Lynch St., Jackson, MS 39217, USA 2 Department of Coastal Sciences; The University of Southern Mississippi; 703 East Beach Drive, Ocean Springs, MS 39564 ABSTRACT It is well known that the global seagrass beds have been declining due to combining effects of natural/anthropogenic disturbances. Restoration efforts have focused on revegetation of the lost seagrass species, which may well work in cases the seagrass loss is recent and the habitat quality has not been altered substantially. Recent studies in several estuaries in the U.S. report the similar change in the seagrass community structures: much of the habitats previously dominated by stable seagrasses (Thalassia testudinum and Syringodium filiforme in tropical and Zostera marina in temperate regions) are now replaced by Ruppia maritima, an opportunistic, pioneer species that is highly dependent on sexual reproduction. The relative increases of R. maritima in seagrass habitats indicate that: (1) the coastal environmental quality has been altered to be more conducive to this species; (2) the quality of environmental services that seagrass beds play also have been changed; and (3) strategies for seagrass restoration and habitat management need to be adjusted. Unlike Zostera or Thalassia, Ruppia maritima beds are known for their seasonal and annual fluctuations. The authors’ previous and on-going research and restoration efforts as well as literature reviews are presented to discuss the causes for and the potential impacts of this change in seagrass community on the coastal ecosystem and future restoration strategies. Keywords: seagrass, Ruppia maritima, coastal, estuaries. * Tele: 601-979-3912; Fax: 601-979-5853; E-mail: [email protected] * Tele: 228 872 4200; Fax 228 872 4204; E-mail: [email protected] 2 Hyun Jung Cho, Patrick Biber and Cristina Nica CHANGES IN COASTAL ENVIRONMENT AND SEAGRASS BEDS Located at the land-water interface, coastal areas are affected by both land and ocean processes. In addition, the low-lying coastal areas and estuaries are particularly prone to the environmental modifications resulted from global climate change. Coastal wetlands have been lost at alarming rates in some areas (as high as 100 km2/year in Louisiana) [11] due to numerous factors that include, but not limited to: (1) levee construction along major rivers that isolate the rivers from supplying sediment and nutrients for delta formation and wetland development; (2) subsidence and global warming that attribute to the Relative Sea Level Rise (RSLR), (3) wave energy and storms; (4) saltwater intrusion to freshwater wetlands, and (5) development for human usages. Habitat loss and environmental changes in shallow coastal areas will likely continue with the trend of global warming that accelerates sea level rise, augments the frequency and intensity of extreme weather conditions such as hurricanes and extreme El Niño Southern Oscillation events [40]. Vegetation communities are often the fundamental components and the keystones of the coastal ecosystems [33]. Submerged aquatic vegetation (SAV), a unique group of vascular plants that have adapted to live underwater, ranges from marine seagrasses to freshwater angiosperms. Coastal seagrass beds: are among the most productive ecosystems in the world; perform a number of vital ecological functions in chemical cycling and physical modification of the water column and sediments; and provide food and shelter for commercially and ecologically important organisms [3, 22, 30]. With the environmental changes listed above, seagrass beds have reportedly been declining globally. Examples include: losses of large beds of Zostera spp. (eelgrass) from algal competition, poor water quality, wasting disease, impacts of shellfisheries, air exposure due to sedimentation, light reduction from eutrophication, and prop scars in temperate regions; reductions of the beds of Posidonia spp. due to modifications brought by dredging, shoreline modification and constructions, light limitation from algal growths, competition from introduced species, increased water temperature in Australia and the Mediterranean [43, 21, 19]. In more tropical areas, large beds of Thalassia testudinum (turtlegrass), Halodule wrightii (shoalgrass), and Syringodium filiforme (manateegrass) have been significantly reduced from similar causes [19]. While it is true that global seagrass habitats are declining due to numerous anthropogenic activities that also exacerbate impacts of natural processes, studies have reported expansion of the SAV species, Ruppia maritima L., into the areas that were previously occupied by other seagrass species, especially after disturbances such as hurricanes [7], salinity changes [18, 29] and extreme meteorological events such as El Niño Southern Oscillation [24, 9]. During the 2007 Estuarine Research Federation conference (http://www.erf.org/erf2007/ERF07 Program.pdf) held in Providence, Rhode Island, USA, several presentations on studies conducted in the U.S. estuaries reported the changes in the seagrass community structures: much of the habitats previously dominated by stable seagrasses (T. testudinum and S. filiforme in tropical and Zostera marina in temperate regions) are now replaced by R. maritima, an opportunistic, pioneer SAV species that is highly dependent on sexual reproduction. The Rise of Ruppia in Seagrass Beds 3 CHARACTERISTICS OF RUPPIA MARITIMA Wigeongrass, R. maritima, is a euryhaline species that tolerates a wide range of salinities from near-freshwater to hypersaline conditions [31, 29], which is why many scientists do not consider it as a true seagrass species [30]. Because of its sporadic occurrence in low salinity habitats and peripheral/opportunistic growth in marine environments, its importance has been underestimated compared to other seagrass species. However, R. maritima is the most widely distributed cosmopolitan seagrass species occurring in broad latitudinal ranges in both northern and southern hemispheres [44, 42]. Ruppia maritima not only consists of populations that are distributed throughout the salinity zones, but also withstands abrupt salinity pulses [45, 29]. It grows better in nutrient- enriched environments that can be stressful to other seagrasses [4] and has a broader temperature tolerance [31]. Being able to rapidly reproduce sexually and asexually, R. maritima can colonize into a bare habitat, grow, and establish quickly. In ephemeral lagoons or estuarine environments with fluctuating water levels, water movements, and salinity, the plants produce an enormous number of seeds (several thousands to tens of thousands seeds per square meter) [24, 32, 10, 25]. The seeds that are protected by sturdy seed coats can resist harsh conditions such as desiccation [26, 8] or even gut-passages of waterfowl and fish, which also aids in long-distance dispersal of the propagules [1, 15, 6, 14]. It is still controversial among the seagrass experts in predicting how global climate change would affect seagrass habitats. While there is little doubt that the climate change will increase the rates of habitat loss and degradation for seagrass beds, Orth et al. [38] noted that the increases in water temperature and CO2 concentrations, when not linked to their indirect effects, may provide a more favorable environment to tropical seagrass species, but they also warned that the current rates of environmental changes may be too fast for adequate adaptation by the species. Considering the traits of R. maritima, the species’ relative abundance and ecological importance are expected to grow in the global seagrass community with the changing climate and environment [24, 18, 25]. The relative increases of R. maritima in seagrass habitats indicate that: (1) the coastal environmental quality has been altered to be more conducive to this species; (2) the quality of environmental services that seagrass beds play also have been changed; and (3) strategies for seagrass restoration and habitat management need to be adjusted. Compared to Zostera or Thalassia beds, R. maritima dominated beds are known for their seasonal and annual fluctuations [12, 31, 35, 18, 29, 7]. Ruppia-dominated beds also have lower peak biomass and productivity than Thalassia or Zostera beds, which would affect food webs [18]. The fauna that rely on resources in the fluctuating seagrass beds will also increase their exposure to predators due to frequent movements, which will also negatively affect survival and reproduction of the predators, who need to spend more time/energy to find prey. DO WE NEED TO RESTORE RUPPIA BEDS? The decline of overall seagrass beds, an essential nursery habitat, directly impacts the marine fishing industry. For example, the economic valuation of the fisheries industry in Mississippi provided by the Center for Fisheries Research and Development at the University 4 Hyun Jung Cho, Patrick Biber and Cristina Nica of Southern Mississippi indicates there are more than 50 species of finfish and shellfish that are commercially harvested in state waters with a market value of $900 million in 2003, and a recreational industry valued conservatively at over $400 million in 2000 [39]. Clearly, loss of habitat would
Load more

Recommended publications
  • Zostera Japonica and Zostera Marina) in Padilla Bay, Washington Annie Walser Western Washington University
    Western Washington University Western CEDAR WWU Graduate School Collection WWU Graduate and Undergraduate Scholarship 2014 A study of pore-water sulfide nda eelgrass (Zostera japonica and Zostera marina) in Padilla Bay, Washington Annie Walser Western Washington University Follow this and additional works at: https://cedar.wwu.edu/wwuet Part of the Marine Biology Commons Recommended Citation Walser, Annie, "A study of pore-water sulfide nda eelgrass (Zostera japonica and Zostera marina) in Padilla Bay, Washington" (2014). WWU Graduate School Collection. 350. https://cedar.wwu.edu/wwuet/350 This Masters Thesis is brought to you for free and open access by the WWU Graduate and Undergraduate Scholarship at Western CEDAR. It has been accepted for inclusion in WWU Graduate School Collection by an authorized administrator of Western CEDAR. For more information, please contact [email protected]. A STUDY OF PORE-WATER SULFIDE AND EELGRASS (ZOSTERA JAPONICA AND ZOSTERA MARINA) IN PADILLA BAY, WASHINGTON By Annie Walser Accepted in Partial Completion Of the Requirements for the Degree Master of Science Kathleen Kitto, Dean of the Graduate School ADVISORY COMMITTEE Chair, Dr. David Shull Dr. Sylvia Yang Dr. John Rybczyk MASTER’S THESIS In presenting this thesis in partial fulfillment of the requirements for a master’s degree at Western Washington University, I grant to Western Washington University the non-exclusive royalty-free right to archive, reproduce, distribute, and display the thesis in any and all forms, including electronic format, via any digital library mechanisms maintained by WWU. I represent and warrant this is my original work, and does not infringe or violate any rights of others.
    [Show full text]
  • Growth and Population Dynamics of Posidonia Oceanica on the S~Anishmediterranean Coast: Elucidatina Seacrrass Decline
    MARINE ECOLOGY PROGRESS SERIES Vol. 137: 203-213, 1996 Published June 27 Mar Ecol Prog Ser Growth and population dynamics of Posidonia oceanica on the S~anishMediterranean coast: elucidatina seacrrass decline Nuria ~arba'l*,Carlos M. ~uarte',Just cebrianl, Margarita E. ~allegos~, Birgit Olesen3, Kaj sand-~ensen~ 'Centre dlEstudis Avanqats de Blanes, C.S.I.C., Cami de Santa Barbara sin, E-17300 Blanes, Girona, Spain 'Departamento de Hidrobiologia, Universidad Autonoma Metropolitana- Iztapalapa, Michocan y Purisima, col. Vicentina, AP 55-535, 09340 Mexico D.F., Mexico 3Department of Plant Ecology, University of Aarhus, Nordlandsvej 68, DK-8240 Risskov. Denmark 'Freshwater Biological Laboratory. University of Copenhagen, 51 Helsingersgade, DK-3400 Hillered. Denmark ABSTRACT: The growth and population dynamics of Posidonia oceanica were examined in 29 mead- ows along 1000 km of the Spanish Mediterranean coast (from 36"46' to 42"22' N). oceanica devel- oped the densest meadows (1141 shoots m-') and the highest aboveground biomass (1400 g DW m") between 38 and 39"N. P. oceanica shoots produced, on average, 1 leaf every 47 d, though leaf forma- tion rates in the populations increased from north to south (range 5 7 to 8.9leaves shoot-' yr-'). P ocean- ica is a long-living seagrass, with shoots able to live for at least 30 yr P, oceanica recruited shoots at low rates (0.02 to 0.5 In units yr-l) which did not balance the mortality rates (0.06 to 0.5 In unlts yr.') found in most (57 %) of the meadows. If the present disturbance and rate of decline are maintained, shoot den- sity is predicted to decline by 50% over the coming 2 to 24 yr.
    [Show full text]
  • Global Seagrass Distribution and Diversity: a Bioregional Model ⁎ F
    Journal of Experimental Marine Biology and Ecology 350 (2007) 3–20 www.elsevier.com/locate/jembe Global seagrass distribution and diversity: A bioregional model ⁎ F. Short a, , T. Carruthers b, W. Dennison b, M. Waycott c a Department of Natural Resources, University of New Hampshire, Jackson Estuarine Laboratory, Durham, NH 03824, USA b Integration and Application Network, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USA c School of Marine and Tropical Biology, James Cook University, Townsville, 4811 Queensland, Australia Received 1 February 2007; received in revised form 31 May 2007; accepted 4 June 2007 Abstract Seagrasses, marine flowering plants, are widely distributed along temperate and tropical coastlines of the world. Seagrasses have key ecological roles in coastal ecosystems and can form extensive meadows supporting high biodiversity. The global species diversity of seagrasses is low (b60 species), but species can have ranges that extend for thousands of kilometers of coastline. Seagrass bioregions are defined here, based on species assemblages, species distributional ranges, and tropical and temperate influences. Six global bioregions are presented: four temperate and two tropical. The temperate bioregions include the Temperate North Atlantic, the Temperate North Pacific, the Mediterranean, and the Temperate Southern Oceans. The Temperate North Atlantic has low seagrass diversity, the major species being Zostera marina, typically occurring in estuaries and lagoons. The Temperate North Pacific has high seagrass diversity with Zostera spp. in estuaries and lagoons as well as Phyllospadix spp. in the surf zone. The Mediterranean region has clear water with vast meadows of moderate diversity of both temperate and tropical seagrasses, dominated by deep-growing Posidonia oceanica.
    [Show full text]
  • VARIATION in SETTLEMENT and LARVAL DURATION of Klng GEORGE WHITING, SILLAGINODES PUNCTATA (SILLAGINIDAE), in SWAN BAY, VICTORIA, AUSTRALIA
    BULLETIN OF MARINE SCIENCE, 54(1): 281-296, 1994 VARIATION IN SETTLEMENT AND LARVAL DURATION OF KlNG GEORGE WHITING, SILLAGINODES PUNCTATA (SILLAGINIDAE), IN SWAN BAY, VICTORIA, AUSTRALIA Gregory P. Jenkins and Helen M. A. May ABSTRACT Otoliths were examined from late-stage larvae and juveniles of King George whiting, Sillaginodes punctata, collected from Swan Bay in spring 1989. Increments in otoliths of larval S. punctata are known to be formed daily. A transition in the microstructure of otoliths from late-stage larvae was apparently related to environmental changes associated with entry to Port Phillip Bay. The pattern of abundance of post-larvae of S. punctata in fortnightly samples supported the contention that the transition was formed immediately prior to "set- tlement" in seagrass habitats. Backcalculation to the otolith transition suggested that five cohorts had entered Swan Bay, each approximately 10 days apart, from late September to early November. Stability of this pattern for juveniles from sequential samples indicated that otolith increments continued to be formed daily in the juvenile stage. The pattern of settlement was consistent for two sites within Swan Bay. The larval phase of King George whiting settling in Port Phillip Bay was extremely long and variable, ranging from approximately 100 to 170 days. Age at settlement was more variable than length, and growth rate at settlement was I I extremely slow, approximately 0.06 mm ·d- • • Backcalculated hatching dates ranged from April to JUly. July. Increment widths in the larval stage suggest that growth slows after approxi- mately 45 to 75 days; beyond which individuals are in a slow growth, competent stage of 40 to 100 days.
    [Show full text]
  • Proximal Analysis of Seagrass Species from Laguna De Términos, Mexico
    Hidrobiológica 2015, 25 (2): 249-255 Proximal analysis of seagrass species from Laguna de Términos, Mexico Análisis proximal de los pastos marinos de la Laguna de Términos, México Erik Coria-Monter and Elizabeth Durán-Campos Programa de Doctorado en Ciencias Biológicas y de la Salud. División de Ciencias Biológicas y de la Salud. Universidad Autónoma Metropolitana. México Calzada del Hueso 1100, Col. Villa Quietud, Delegación Coyoacán, D. F., 04960. México e-mail: [email protected] Coria-Monter E. & E. Durán-Campos. 2015. Proximal analysis of seagrass species from Laguna de Términos, Mexico. Hidrobiológica 25 (2): 249-255. ABSTRACT This paper examines chemical nutritional aspects of three seagrass species (Thalassia testudinum König, Halodule wrightii Ascherson, and Syringodium filiforme Kützing) found at Laguna de Términos, Campeche, Mexico during the rainy season of 2004, following analysis methods described by the Association of Official Analytical Chemists. High protein (8.47- 10.43%), high crude fiber (15.70-19.43%), high ash (23.43-38.77%) high nitrogen-free extract contents (37.27-45.37%), and low lipid levels (0.83-2.13%) were common features of the three species analyzed. Given its chemical contents and the World Health Organization reference standards, particularly the high protein (10.43%), high ash (23.43%), high fiber (19.43%), high nitrogen-free extract (45.37%) and low lipids (2.13%), S. filiforme appears to be a noteworthy potential dietary supplement and a nutrient source for human consumption. Another use of this high-protein seagrass could be in producing food for aquaculture fish. Key words: Halodule wrightii, Laguna de Términos, proximate analysis, Syringodium filiforme, Thalassia testudinum.
    [Show full text]
  • Alphabetical Lists of the Vascular Plant Families with Their Phylogenetic
    Colligo 2 (1) : 3-10 BOTANIQUE Alphabetical lists of the vascular plant families with their phylogenetic classification numbers Listes alphabétiques des familles de plantes vasculaires avec leurs numéros de classement phylogénétique FRÉDÉRIC DANET* *Mairie de Lyon, Espaces verts, Jardin botanique, Herbier, 69205 Lyon cedex 01, France - [email protected] Citation : Danet F., 2019. Alphabetical lists of the vascular plant families with their phylogenetic classification numbers. Colligo, 2(1) : 3- 10. https://perma.cc/2WFD-A2A7 KEY-WORDS Angiosperms family arrangement Summary: This paper provides, for herbarium cura- Gymnosperms Classification tors, the alphabetical lists of the recognized families Pteridophytes APG system in pteridophytes, gymnosperms and angiosperms Ferns PPG system with their phylogenetic classification numbers. Lycophytes phylogeny Herbarium MOTS-CLÉS Angiospermes rangement des familles Résumé : Cet article produit, pour les conservateurs Gymnospermes Classification d’herbier, les listes alphabétiques des familles recon- Ptéridophytes système APG nues pour les ptéridophytes, les gymnospermes et Fougères système PPG les angiospermes avec leurs numéros de classement Lycophytes phylogénie phylogénétique. Herbier Introduction These alphabetical lists have been established for the systems of A.-L de Jussieu, A.-P. de Can- The organization of herbarium collections con- dolle, Bentham & Hooker, etc. that are still used sists in arranging the specimens logically to in the management of historical herbaria find and reclassify them easily in the appro- whose original classification is voluntarily pre- priate storage units. In the vascular plant col- served. lections, commonly used methods are systema- Recent classification systems based on molecu- tic classification, alphabetical classification, or lar phylogenies have developed, and herbaria combinations of both.
    [Show full text]
  • Karyotype Variations in Seagrass (Halodule Wrightii Ascherson￢ﾀﾔ
    Aquatic Botany 136 (2017) 52–55 Contents lists available at ScienceDirect Aquatic Botany journal homepage: www.elsevier.com/locate/aquabot Short communication Karyotype variations in seagrass (Halodule wrightii Ascherson—Cymodoceaceae) a b,∗ a Silmar Luiz da Silva , Karine Matos Magalhães , Reginaldo de Carvalho a Graduate Program in Botany—PPGB and Cytogenetic Plant Laboratory of the Federal Rural University of Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, CEP: 52171-900, Recife, Pernambuco, Brazil b Aquatic Ecosystems Laboratory of the Federal Rural University of Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, CEP: 52171-900, Recife, Pernambuco, Brazil a r t i c l e i n f o a b s t r a c t Article history: Karyotype variations in plants are common, but the results of cytological studies of some seagrasses Received 26 June 2015 remain unclear. The nature of the variation is not clearly understood, and the basic chromosomal num- Received in revised form 5 August 2016 ber has still not been established for the majority of the species. Here, we describe karyotype variations in Accepted 15 September 2016 the seagrass Halodule wrightii, and we suggest potentially causative mechanisms involving cytomixis and Available online 16 September 2016 B chromosomes. We prepared slides using the squashing technique followed by conventional Giemsa and C-banding, and silver nitrate and a CMA/DAPI staining. Based on intraspecific analysis, the diploid chromo- Keywords: some number of H. wrightii exhibited a variation from 2n = 24 to 2n = 39; 2n = 38 was the most frequent. In Cytomixis Seagrass general, we characterized the karyotype as an asymmetrical, semi-reticulated interphase nucleus with a chromosomally uniform condensation pattern.
    [Show full text]
  • Introduction to Common Native & Invasive Freshwater Plants in Alaska
    Introduction to Common Native & Potential Invasive Freshwater Plants in Alaska Cover photographs by (top to bottom, left to right): Tara Chestnut/Hannah E. Anderson, Jamie Fenneman, Vanessa Morgan, Dana Visalli, Jamie Fenneman, Lynda K. Moore and Denny Lassuy. Introduction to Common Native & Potential Invasive Freshwater Plants in Alaska This document is based on An Aquatic Plant Identification Manual for Washington’s Freshwater Plants, which was modified with permission from the Washington State Department of Ecology, by the Center for Lakes and Reservoirs at Portland State University for Alaska Department of Fish and Game US Fish & Wildlife Service - Coastal Program US Fish & Wildlife Service - Aquatic Invasive Species Program December 2009 TABLE OF CONTENTS TABLE OF CONTENTS Acknowledgments ............................................................................ x Introduction Overview ............................................................................. xvi How to Use This Manual .................................................... xvi Categories of Special Interest Imperiled, Rare and Uncommon Aquatic Species ..................... xx Indigenous Peoples Use of Aquatic Plants .............................. xxi Invasive Aquatic Plants Impacts ................................................................................. xxi Vectors ................................................................................. xxii Prevention Tips .................................................... xxii Early Detection and Reporting
    [Show full text]
  • Posidonia Paper.Docx
    Epiphyte accruel patterns and effects on Posidonia oceanica By Emily Hardison and Scott Borsum Abstract This study focuses on the relationship between Posidonia oceanica leaves and the epiphytes that live on those leaves at Stareso Research center in Calvi Bay, Corsica. We determine patterns of epiphyte accrual along Posidonia oceanica leaves for depths of 5m, 10m, 15m, and 20m and calculate the abundance of epiphytes across this depth range and the biomass of epiphytes in Posidonia oceanica bed at each depth, through in water measurements and characterizing epiphyte loads of samples brought onshore. We show that epiphytes aggregate in depth specific and leaf-side specific patterns along Posidonia leaves, cause degradation of live Posidonia tissue, and contribute a significant amount of biomass to Posidonia oceanica beds and detritus. We attempt to explain why certain patterns of epiphyte accrual are seen by determining that the convex side of the leaf most commonly faces up towards the sun. Introduction Posidonia oceanica is a protected endemic seagrass species in the Mediterranean Sea. This species is particularly interesting because of the large role it plays in maintaining a healthy and diverse Mediterranean ecosystem. It grows in vasts meadows and provides habitats, food, and nursery areas for a wide array of species (Boudouresque C. et al., 2006). Despite its energy expensive lifestyle, Posidonia is able to survive in the nutrient poor waters of the Mediterranean Sea (Lepoint, 2002). Posidonia is often inhabited by epiphytes. Previous research has shown that epiphyte load on Posidonia leaves has a negative relationship with depth (Lopez, 2012). Light attenuates with depth and can therefore become a limiting factor for primary producers, like Posidonia.
    [Show full text]
  • Morpho-Chronological Variations and Primary Production in Posidonia
    Morpho-chronological variations and primary production in Posidonia sea grass from Western Australia Gérard Pergent, Christine Pergent-Martini, Catherine Fernandez, Pasqualini Vanina, Diana Walker To cite this version: Gérard Pergent, Christine Pergent-Martini, Catherine Fernandez, Pasqualini Vanina, Diana Walker. Morpho-chronological variations and primary production in Posidonia sea grass from Western Aus- tralia. Journal of the Marine Biological Association of the United Kingdom, Cambridge University Press, 2004, 84 (5), pp.895-899. 10.1017/S0025315404010161h. hal-01768985 HAL Id: hal-01768985 https://hal.archives-ouvertes.fr/hal-01768985 Submitted on 17 Apr 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. J. Mar. Biol. Ass. U.K. (2004), 84, 895^899 Printed in the United Kingdom Morpho-chronological variations and primary production in Posidonia sea grass from Western Australia P Ge¤rard Pergent* , Christine Pergent-Martini*, Catherine Fernandez*, O Vanina Pasqualini* and Diana Walker O *Equipe Ecosyste' mes Littoraux, Faculty of Sciences,
    [Show full text]
  • 1.3 Impact of Invasive Aquatic Plants on Waterfowl
    1.3 Impact of Invasive Aquatic Plants on Waterfowl Ryan M. Wersal: Minnesota State University Mankato, Mankato MN; [email protected] Kurt D. Getsinger: US Army ERDC, Vicksburg MS; [email protected] Introduction Studies that evaluate the relationship between waterfowl and aquatic plants (native or nonnative) usually focus on the food habits and feeding ecology of waterfowl. Therefore, the purpose of this section is to describe the dynamics of waterfowl feeding in relation to aquatic plants. The habitats used by waterfowl for breeding, wintering and foraging are diverse and change based on the annual life cycle of waterfowl and seasonal conditions of the habitat. For example, waterfowl require large amounts of protein during migration, nesting and molting, and they fulfill this requirement by consuming aquatic invertebrates. As noted in Sections 1.1 and 1.2, a strong relationship exists between high numbers of aquatic invertebrates and diverse aquatic plant communities, so diverse plant communities also play an important role in waterfowl health by hosting the invertebrates needed to subsidize waterfowl migration, nesting and molting. After all, waterfowl native to the US have evolved alongside diverse plant communities that are likewise native to the US and utilize these plants and associated invertebrates to meet their energy needs. Metabolic energy demands of waterfowl are high during the winter months, so waterfowl need foods that are high in carbohydrates such as plant seeds, tubers and rhizomes during winter. Many waterfowl will sometimes abandon aquatic plant foraging while on their wintering grounds and feed instead on high-energy agricultural crops such as wheat, corn, rice and soybeans.
    [Show full text]
  • The Sea-Grasses of Brazil Ligulate, Linear, Leaf-Tip
    Acta Bot. Need. October 512-516 21(5), 1972, p. The sea-grasses of Brazil C. den Hartog Rijksherbarium, Leiden There is still hardly anything known aboutthe occurrence of sea-grasses in South America. The number of records is extremely small. Therefore, one wonders whether these plants are extremely rare or absent along long stretches of coast, whether it is that have been overlooked or just they by botanists. It seems that the latterapplies to the coast of Brazil, from where up to nowonly two collections had been recorded (Setchell 1934; den Hartog 1970). Thanks to the active, gratefully acknowledged co-operation of Dr. Liliane Forneris (Universidade de Sao Paulo) I received a number of sea-grasses from several places along the Brazilian coast. I am also indebted to Dr. Emilia Santos (Museu Nacional, Rio de Janeiro) and Dr. Graziela M. Barroso (Jardim Botanico, Rio de Janeiro) for and sending me a specimen a photograph, respectively, of Halophila decipiens. Further, I am grateful to Dr. V. J. H. de Jilovice de Sternberg (Com- panhia ‘Algimar’, Rio de Janeiro) for his co-operation in obtaining material. At present there are 5 species now known from Brazil. KEY TO THE SEA-GRASSES OF BRAZIL 1. Leaves with 3 Tannin cells ligulate, linear, nerves. present. 2. Leaf-tip bicuspidate; leaves Va-l mm wide 1. Halodule wrightii obtuse with 2. Leaf-tip or emarginate, very faintly developed lateral teeth, or without such teeth; leaves wider than 1 mm. 3. Leaf-tip emarginate 2. Halodule emarginata 3. Leaf-tip obtuse 3. Halodule lilianeae 1.
    [Show full text]