Characteristics of benthic foraminifera inhabiting rocky reefs in

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  • STATE OF ISRAEL

    THE MINISTRY OF NATIONAL INFRASTRUCTURES

    Office of the Chief Scientist

    Characteristics of benthic foraminifera

    inhabiting rocky reefs in northern Israeli

    Mediterranean shelf

    Orit Hyams-Kaphzan, Lydia Perelis Grossowicz and

    Ahuva Almogi-Labin

    The Geological Survey of Israel

    20.8.20.4

    GSI/36/2014 Report: ES-20-2014

  • 3. Recipient Accession No. 2. 1. Publication No. ES-20-14

    5.Publication Date

    August, 2014

    4.Title: Characteristics of benthic

    foraminifera inhabiting rocky reefs in

    northern Israeli Mediterranean shelf

    6. Performing Organiz. Code

    8. Performing Organiz. Rep. No.

    GSI/36/2014

    7. Author (s) Orit Hyams-Kaphzan, Lydia

    Perelis Grossowicz and Ahuva Almogi-Labin

    10. Project/ Task / Work Unit No. 9. Performing Organization Name and Address Geological Survey of Israel, Jerusalem 95501

    11. Contract No. 212-17-024

    13. Type of report and period covered

    Final report

    12.Sponsoring Organization (s) Name and

    Address The Ministry Of Energy and Water Resources

    P.O.B. 36148, 9136002 Jerusalem 14. Sponsoring Organiz. Code

    15. Supplementary Note: This report is part of a larger research project:

    16. Abstract: Hard bottom habitats common in the northern Israeli shelf constitute a highly

    diverse marine ecosystem rich in macroalgae and calcareous organisms. This ecosystem suffered

    during the last few decades from continuous disturbance due to anthropogenic intervention. In

    order to tackle this complex ecosystem we initiated a pilot study in collaboration with IOLR,

    with focus on several key faunal groups. Benthic foraminifera, known to be sensitive indicators

    of this ecosystem were sampled from the rocky reefs of Akhziv (AK) and Carmel Head (CH) by

    scuba diving. Different macroalgae species accommodating the live epiphytic benthic

    foraminifera were sampled twice a year at AK and in each season at CH in 3 depth intervals

    between 5-20 m, during 2013-4. The numerical abundance of the group ranges between 170-

    3500 #/10cc (wet macroalgae volume) without any significant difference in standing stocks

    within regions, water depths or macroalgae preference. In total 77 benthic foraminifera species

    were identified, 71 in CH and only 43 at AK. Species richness per site varied between 3 and 42

    with higher values at CH. 25% of all species were aliens, mostly Lessepsian, and comprise on

    average 70% - 84% of the numerical abundance of AK and CH respectively. Cluster analysis

    using benthic foraminifera relative abundance data did not correlate with the different

    macroalgae species, water depths or seasonality, indicating that the foraminiferal community in

    the two regions is quite homogenous. Amphistegina lobifera a Lessepsian migrant is by far the

    most common species on the Israeli rocky reefs occurring in all samples and comprising 18-93%

    of the foraminiferal community. Textularia agglutinans another common species occurs in

    higher numbers in AK while Pararotalia calcariformata is more restricted to the CH region. In

    some CH sites this species predominate the assemblage, indicating the adjustment of this species

    to deeper water niches. This study indicates that Israeli rocky reefs represent a dynamic

    ecosystem prone to rapid changes that needs to be monitored regularly.

    17. Keywords: Benthic foraminifera, Rocky reefs, Mediterranean, alien species , , ,

    20. Security Class 19. Security Class 18. Availability Statement

    22. Price 21. 32 Pages

  • 2

    Abstract

    Hard bottom habitats common in the northern Israeli shelf constitute a highly diverse

    marine ecosystem rich in macroalgae and calcareous organisms. This ecosystem suffered

    during the last few decades from continuous disturbance due to anthropogenic

    intervention. In order to tackle this complex ecosystem we initiated a pilot study in

    collaboration with IOLR, with focus on several key faunal groups. Benthic foraminifera,

    known to be sensitive indicators of this ecosystem were sampled from the rocky reefs of

    Akhziv (AK) and Carmel Head (CH) by scuba diving. Different macroalgae species

    accommodating the live epiphytic benthic foraminifera were sampled twice a year at AK

    and in each season at CH in 3 depth intervals between 5-20 m, during 2013-4. The

    numerical abundance of the group ranges between 170-3500 #/10cc (wet macroalgae

    volume) without any significant difference in standing stocks within regions, water

    depths or macroalgae preference. In total 77 benthic foraminifera species were identified,

    71 in CH and only 43 at AK. Species richness per site varied between 3 and 42 with

    higher values at CH. 25% of all species were aliens, mostly Lessepsian, and comprise on

    average 70% - 84% of the numerical abundance of AK and CH respectively. Cluster

    analysis using benthic foraminifera relative abundance data did not correlate with the

    different macroalgae species, water depths or seasonality, indicating that the

    foraminiferal community in the two regions is quite homogenous. Amphistegina lobifera

    a Lessepsian migrant is by far the most common species on the Israeli rocky reefs

    occurring in all samples and comprising 18-93% of the foraminiferal community.

    Textularia agglutinans another common species occurs in higher numbers in AK while

    Pararotalia calcariformata is more restricted to the CH region. In some CH sites this

    species predominate the assemblage, indicating the adjustment of this species to deeper

    water niches. This study indicates that Israeli rocky reefs represent a dynamic ecosystem

    prone to rapid changes that needs to be regularly monitored.

  • 3

    1. Introduction

    1.1 Background

    Hard bottom habitats are distributed along the Mediterranean Israeli coast from zero

    down to ~100 m depth being more abundant in the northern part of the Israeli shelf

    (Almagor and Hall, 1984). This marine ecosystem is highly diverse, unlike the more

    common sandy soft sediment habitat, resembling in its wealth low latitudes rocky reefs

    (Rilov, 2014). For many of the Mediterranean and the Atlantic-Mediterranean species the

    Israeli coast represents the eastern end of distribution. In addition this region, and mainly

    the rocky habitat is affected badly by invasive species that spread from the Red Sea via

    the Suez Canal into our coasts and alter the community structure (Hyams et al., 2002,

    Hyams-Kaphzan et al., 2008; Rilov and Galil, 2009). This complex habitat, rich in

    macroalgae, micro- and macrofauna and fish is also one of the most vulnerable

    ecosystems along the Israeli coast that might be affected by the rapid increase in sea

    surface temperature (SST), salinity (SSS) and changes in the trophic levels (Herut et al.,

    2000; Gertman and Hecht, 2002). So far, little attention was given to study this unique

    and complex ecosystem. In order to be able to detect and follow changes that result from

    natural variability in space and time and compared it to changes caused by anthropogenic

    contamination we initiated this study on the characteristics of the foraminiferal group, an

    important component of the hard bottom ecosystem of the Israeli coast (Hyams-Kaphzan

    et al., 2008; Gruber, 2006; Lazar, 2007). This study, carried out in collaboration with Gil

    Rilov from IOLR, is an extensive effort to establish an ecological baseline and test a

    possible monitoring program of this important ecosystem. In this study the distribution of

    living benthic foraminifera was investigated in two rocky regions, in different seasons,

    water depths and on different macroalgae species, in order to capture the full numerical

    abundance range and species diversity and assemblage composition in this highly

    variable and complex ecosystem.

    1.2 Benthic foraminifera

    Benthic foraminifera are known as the most diverse group of microscopic organisms with

    calcareous or agglutinated shell alive today (Sen Gupta, 1999). As unicellular organisms

    with short reproductive cycle and fast growing rates, they show a quick response to

    changes in environmental conditions and serve therefore as extremely sensitive indicators

    of environmental changes due to anthropogenic contaminations and SST rise (e.g. Alve,

    1995; Jorissen et al., 1995; Hyams-Kaphzan et al., 2009; Arieli et al., 2011). The main

    factors determining the abundance of benthic foraminifera in the shallow water of the

    Israeli Mediterranean Sea are food availability, substrate type and seasonality (Gruber,

    2006; Hyams-Kaphzan et al., 2008, 2009; Arieli et al., 2011). Species diversity and

    abundance is the highest at 3040 m water depths, mainly in the carbonate-rich substrate

  • 4

    (including hard substrate) and on macroalgae of the subtidal zone. The lowest values

    were encountered at depths of 39 m, in sandy substrate where high wave energy and

    lack of food resources act as limiting factors (Hyams-Kaphzan et al., 2008). In the past,

    Gruber (2006) and Arieli et al. (2011) studied foraminifera living on rocky habitats of

    less than 2 m water depth. These foraminifera were epiphytic, living on different

    macroalg

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