Modeling Oyster Reef Reproductive Sustainability: Analyzing Gamete Viability, Hydrodynamics, and Reef Structure to Facilitate Restoration of Crassostrea virginica

The eastern oyster is a keystone species and ecosystem engineer. However, restoration efforts of wild oysters are often unsuccessful, in that they do not produce a robust population of oysters that are able to successfully reproduce. Furthermore, the dynamics of wild oyster fertilization is not yet well understood. Through conducting an experiment predicated on quantifying the influence of elementary aspects of fertilization kinetics—sperm concentration, gamete age, and success rate—we found that, as stochastic as the mating process may seem, there are correlations which fundamentally serve as the framework for assessing long-term sustainability, reef structure, and hydrodynamic parameters in relation to fertilization. We then focused on mathematically defining a procedure which simulated a concentration distribution of a single sperm and egg release where there existed conditions necessary for breeding to take place. We found a very significant impact of both gamete age and sperm concentration on fertilization rate (p < 0.0001). Our hydrodynamic model demonstrates that distance can also drastically influence broadcast spawning. This could be used as a foundation for developing a flexible model for wild oyster fertilization based on placement, initial seawater conditions, and size of the starting population. The results of this research could be implemented into a more user-friendly program which would accept multiple variables as inputs and output the probability of fertilization given arbitrary values. By accounting for environmental deviations, this generalization would increase its compatibility with the public and actualize the project’s intended purpose: enhance the planning of oyster reef restoration projects.

Specific minerals in bryozoan bioherms and polychaetian limestones (Kazanthip reserve, Crimea)

The object of our research is the Kazantip Cape (Kerch Peninsula, Crimea). Its attraction is a ring-shaped rock massif composed of bryozoans previously considered to be a reef structure growing on the limbs of rising brachyanticline about 8 million years ago. Application of complex of investigating methods show that clay deposits underlying bryozoan structure are composed of expandable mixed-layered minerals, smectite, kaolinite, chlorite, illite with accessory minerals (zircon, monazite, ilmenite). These clays are the result of eruption of fossilized analogue of mud volcano. This process was accompanied by unloading of cold gas-fluid seepage. Specific mineralization (barite, celestine, strontianite, authigenic minerals of rare-earth elements and manganese) of bryozoan’s bioherms indicates that the seep process continued even after the waning of mud volcanism.

NUMERICAL INVESTIGATION OF PLUNGING BREAKERS OVER A POROUS ARTIFICIAL SURF REEF

This paper presents the results of a numerical investigation of breaking waves over an artificial surf reef (ASR). In the surfing industry, it has become common to establish artificial surf reefs to enhance the surfability at popular surf locations, or to attract surfers to new locations. Besides enhancing the surfing quality, an ASR can also be seen as a submerged detached breakwater, which is a well known type of structure for coastal protection. The construction of an ASR can therefore have the additional purpose of acting as a measure for coastal protection. Hereby the ASR becomes a multi-purpose reef. In this paper, we focus on two aspects of an ASR in relation to the effect of the porous reef: 1) a general analysis of the hydrodynamics of a plunging breaker over a reef, and 2) evaluation of specific parameters for describing the surfability and safety of the plunging breaker. The novelty of the work presented lays in the detailed inclusion of the porous reef structure in a numerical model that is applied for designing and evaluating an ASR.

Oil and Gas Reef Facies Reservoir 3D Geological Modeling

The paper presents a technique of three-dimensional geological modeling of one of the most complex formations, reef deposits. The research objective is an investigation of how the reef structure genesis influences the three-dimensional geological grid of reef mass. Using the paleogeographic and paleofacies methods of investigation, the conceptual and three-dimensional geological models of a natural reservoir have been constructed.