Algae and Cyanobacteria Diversity and Bioindication of Long-Term Changes in the Hula Nature Reserve, Israel

Lake Hula, the core of one of the most extensive wetland complexes in the Eastern Mediterranean, was drained in 1951–1958. However, about 350 hectares of papyrus marshes were allocated in the southwestern part of the previous lake and became the Hula Nature Reserve status, the first of two wetlands in Israel included in the Ramsar List of Wetlands of International Importance. The list of algae and cyanobacteria species of Lake Hula was compiled by us for the first time based on data from publications of 1938–1958, as well as our research in the Hula Nature Reserve, obtained within the framework of the monitoring program for 2007–2013. The list includes 225 species and intraspecies of algae and cyanobacteria belonging to eight phyla. The dynamics of the species richness of algae and cyanobacteria flora for 1938–2013 are shown. Species-bioindicators of water quality have been identified, and the change in their composition by ecological groups for a period of about a hundred years has been shown. Based on the species richness of algae communities, water quality indices were calculated with particular attention to changes in trophic status during the study period. The algae flora of Lake Hula and Hula Nature Reserve was found to be similar, but bioindication has revealed an increase in salinity and organic pollution in recent years.

Pleistocene amphibians and squamates from the Upper Jordan Rift Valley, Gesher Benot Ya’aqov and Nahal Mahanayeem Outlet (MIS 20–18 and MIS 4/3)

ABSTRACTThe Acheulian site of Gesher Benot Ya’aqov (GBY) and the Mousterian site of Nahal Mahanayeem Outlet (NMO) are open-air sites situated on the bank of the Upper Jordan River at its southern estuary in the Hula Valley, Israel. Both sites were deposited on the shore of a paleo-Lake Hula, a shallow body of water that persisted throughout a considerable part of the Pleistocene as a fresh-water lake. Most of the amphibian and squamate taxa recovered are aquatic species related to the natural biota of the Hula Valley, alongside some terrestrial species. Twelve amphibian and squamate taxa were recovered at each site. Most of the species recovered from the archaeological contexts do not differ from extant Hula Valley amphibians and squamates, with the exception of a varanid (Varanussp.) recovered at GBY and the possible presence of the eastern fourlined ratsnake (cf.Elaphe sauromates). The snake’s presence could indicate slightly cooler conditions during human occupation at NMO. A noteworthy continuity in species presence is observed throughout the many archaeological horizons as well as in comparison to the current Hula basin fauna. This suggests a surprising similarity in environmental conditions over a significant portion of the Quaternary in this region.

The Hula Valley (Israel): From Nature to Anthropogenic Management, A Review

<p>The long history, from Stone-Age period until present, of settling in the HulaValleyis reviewed. This Valley land, 17.7X10³ ha, was mostly covered by swamps and old Lake Hula. Population size of settlers in the Valle and in close vicinity was very small. The swamps in the Valley were mostly (app 85%) covered by <em>Cyperus papyrus</em> vegetation. Three major headwaters discharges were fluxed through the swampy area into Lake Hula from which the Jordan river outflow continued downstream into Lake Kinneret. Anthropogenic usage of the Hula Valley hydrological and vegetation (Papyrus for mats production and grass for cattle grazing) resources were poorly implemented. During the 1950`s of the 20^th century the swamps and the Hula Lake were drained and the entire valley land was converted into agricultural utilization. The significance of that environmental modification is discussed.</p>

ALGAL FLORA IN THE HULA VALLEY—PAST AND PRESENT

Lake Agmon, a small shallow water body (area 1.1 km2, mean depth <lm) was created in April 1994 as part of the Hula restoration project in the dried peat-soils of the Hula Valley. Until ca. 50 years ago, this area was covered with swamps, extending to the north of Lake Hula. We followed changes over time in the abundance and species composition of the algal populations in Lake Agmon over the initial 4 years that followed its creation, consolidated the existing information on the algal populations of the extinct Lake Hula, and compared the Lake Agmon algal populations with those reported from Lake Hula and with those present in Lake Rinneret. Altogether, 276 algal species were found in Lake Agmon, including 140 chlorophytes, 48 euglenophytes, 34 cyanophytes, 31 diatoms, 8 cryptophytes, 8 dinoflagellates, and 4 chrysophytes. A comprehensive species list for Lake Hula was also compiled, based on the limited published accounts. The similarities between the past and present algal communities in the Hula Valley were great: most diatom, dinoflagellate, chrysophyte, euglenophyte, and large chlorophyte and cyanophyte genera that are seen today in Lake Agmon were also reported from Lake Hula. However, the Hula list of genera was shorter than the Lake Agmon list in some particular categories. The lack of most of the nannoplanktonic Chlorococcales, and all cryptophytes and other small flagellates from the Hula list was attributed to different sampling and preservation methods in the early days; the absence of most filamentous cyanobacteria is considered a real difference, possibly resulting from the more eutrophic status of Lake Agmon. Notably, the dinoflagellate Peridinium gatunense, which blooms annually in Lake Kinneret downstream of the Hula Valley, was not recorded in Lake Hula and did not occur in Lake Agmon.